My comments + predictions for now...
Celtic v Barcelona
These two know each other so well right now meeting up yet again this year! Celtic are top of their SPL for now (Gers have like a game in hand I think). Barca are 2nd in La Liga, and if Messi manages to stay uninjured, I'm expected one helluva a display from him. Tight game at Celtic park, Barcelona to dominate them in the return leg.
Lyon v Man Utd
Lyon are top of the league, with the best Goals Scored record, but second best defense...surprise package Nancy have the best D-record Ligue 1! Kallstrom, Gouvou, Benzema, Grosso, Juninho P, Toulalan......this team has quality. But this top team are up against the EPL champs, against one of the world's best - C Ronaldo, Rooney, Ferdinand, Vidic, Evra, Tevez. And then you never know when one of their youth kids pops up, like Eagles or Pique, and scores a goal! It will be a tightly contested affair, with Man United just edging it out on away goals perhaps. It can be argued that Man United's best chance to win the CL was last year. Not much has changed since last season, except for Hargreaves and Tevez - and I definitely pick them to have a good run this year.
Schalke v Porto
Schalke are the lesser favorites here - strong points in Gyan, Rafinha, and Kuranyi...currently in the Bundesliga top 5. They're up against Ferreira's high flying and in-form league leaders - FC Porto, led by Quaresma who's been on awesome form in the SuperLiga (just saw some highlights of the 1-0 win vs. Benfica this morning on TV!!). I predict Porto to take this one. Schalke would choke at this stage, IMO.
Liverpool v Inter
The 2005 champs/2007 finalist, versus the Serie A league leaders. While Inter steamroller through the Serie A, Liverpool are the same story for the past 4-5 years - lounging around the 3rd-5th place position. However, as previous years have shown us, the Merseysiders are by no means a walk in the park. Teams like Roma whether it's UEFA Cup or CL, and Juve in CL have both been defeated by the Reds. Both teams have in common two fearful strikers - Torres and Zlatan. Come next year, Mancini is expected to have increased his side's commanding lead (unless Juve keep racking up wins, and Inter drop form ) so in theory they should be under less pressure for this match. On the other hand, Benitez has experienced some tension from LFC's American owners Hicks and Gillett due to their patchy form...and a home defeat to Man United puts the pressure on Rafa and his men get a result here. I predict Inter to win this by a slim victory.
Roma v Real Madrid
These two capital sides always seem to cross paths. Read Madrid lead La Liga, while 2nd place Roma just lack that extra special element taking them into this big game - Vucinic is on good form ATM, Totti is currently injured (same ankle), Panucci has rediscovered himself, while Taddei, Perrotta, Pizzarro, Mancini, De Rossi contribute to Spalletti's attacking solid team. There's just a lack of some creative element without Totti, and his presence will really make this match a special one. Sergio Ramos, Sneijder, Raul, Robinho, RvN. Real Madrid will win this encounter. Judging from Roma's Man United games (EPL leaders)...I don't see how they will overcome Schuster's Real Madrid. (I am well aware that the "transitive property" x > y & y > z therefore x > z doesn't apply...just using it as a reference, anything can happen!!)
Arsenal v AC Milan
AC Milan lying in mid-table (3 games in hand) are unable to win at home both in Serie A, and recently Coppa Italia (nice goal by Paloschi by the way!) - yet the current CL and "World" Champs will have a tough task against the EPL leaders, Arsenal. Cesc, RvP, Gallas, Hleb, Gilberto, Flamini, Adebayor, Toure, Rosicky - IMO from what I've watched this year, they are definitely the most entertaining team to watch. And not only that, they're getting the results. These kids embarrassed Capello's Juve in the old Highbury. Since 2000, Arsenal's record against Italian clubs is quite impressive, beating Lazio, Roma, Inter, and Juve! AC Milan have a side just oozing with class – Dida, Oddo, Nesta, Maldini, Pirlo, Ambrosini, Rino, Kaka', Gilardino, Ronaldo...definitely a team not to be taken lightly. Milan have done well against Premiership opposition in recent years, namely Man United (three outta four, I believe?) and more recently, Liverpool. I think the old Legion will fall apart, making it the final nail in Carletto's coffin should their unimpressive Serie A form continue. Arsenal will beat Milan, IMO.
Olympiakos v Chelsea
On paper this is a no-brainer. It has Chelsea-win written all over it. But let's not disrespect the Greek side, they've got some decent players and an extremely noisy crowd representing Gate7 (Thryllos!!). Stoltidis, Galletti, Ledesma, Kovacevic...and veteran in goal Nikopolidis! The Greeks are usually trounced in the group stage, seldom win away matches, and when they finally get their act together...they get this huge draw. It will be interesting to see how Olympiakos will do against the famous Chelski - Drogba, Lamps, Kalou, J. Cole, A. Cole, Essien, SWP, Sheva, Ballack. The last time Olympiakos were in the second round, they were within minutes of qualifying to the semi's when, when Antonio Conte's goal silenced the crowd (

roud: ) for Juve to qualify! I think Chelsea will go thru here.
Fenerbahce v Sevilla
When you read this, a casual fan might write this off as the "least fashionable" match. How wrong could they be? These two sides have been playing the most attacking style of football so far in the CL, and I am sure it will be a goal fiesta. Fener have a South American/Brazilian flavor to them - Diego Lugano, Aurelio, Roberto Carlos, Alex, and former Bordeaux striker Deivid. They stunned Inter Milan in their opener with Deivid's fine goal after a brilliant setup! Sevilla, hit with tragic news earlier on this season, but they are moving forward keeping up a good spirit. Juande Ramos has left to Spurs now, and it might be difficult to excel. But we've seen Spanish sides do this before, and IMO this Sevilla side are reminiscent of the Super-Depor side that terrorized many teams in their path. Luis Fabiano, Daniel Alves, Freddy Kanoute, Adriano, Renato, Navas, Keita...are all capable of inflicting damage on any side! It will be a goal fiest...but my prediction - the back2back UEFA Cup champs will just edge it and go thru.