honestly, taking my juve and love of del piero hat off, he should not be there for italy this world cup. it just woudlnt be just for others who are playing better and are yougner.
If Del Piero plays the way he did before the last two matches, then of course it won't be fair if Lippi takes him instead of taking someone who did much better than Ale (for example, Di Natale).
But if Del Piero plays well, then it won't be fair to Del Piero if Lippi takes someone like Rossi, who is having a bad season and did nothing remarkable to deserve a spot in the NT team.
As for Del Piero's chances to make the WC team, much of it depends on him and how he'll play till the end of the season. Looking at the other available strikers, it's obvious that none of them is great enough and, apart from Di Natale, none of them is having a great season that will guarantee a WC spot. Del Piero still has a chance to make the squad.
Since Cassano isn't even a candidate, then I believe that the 4-5 strikers that will make it to the WC will be picked from the 8 strikers that played in the qualifiers:
1. Gilardino, Played on 5 matches (4 as a starter), 324 minutes, 4 goals
2. Di Natale, Played on 7 matches (6 as a starter), 419 minutes, 2 goals
3. Iaquinta, Played on 6 matches (5 as a starter), 431 minutes, 2 goals
4. Pazzini, Played on 2 matches (1 as a starter), 34 minuts, 1 goal
5. Rossi, Played on 3 matches (2 as a starter), 159 minutes, 0 goals
6. Quagliarella, Played on 4 matches (1 as a starter), 139 minutes, 0 goals
7. Toni, Played on 3 matches (2 as a starter), 132 minutes, 0 goals
8. Del Piero, Played on 1 match (0 as a starter), 34 minutes, 0 goals
Gila, Pazzini and Toni are target men so they're not Del Piero's rivals for a place in the team. The other 4 are Di Natale, Iaquinta (could also be a target man), Quagliarella and Rossi.
Actually, I see only Di Natale, Quagliarella and Rossi as Ale's rivals because I'm pretty sure that Lippi will take 5 attackers at the world cup, two of them will be Iaquinta and Gilardino for sure, while the third one will be a target man, probably Pazzini.
So for the other 2 places, for which Di Natale, Quag, Rossi and Ale will fight, assuming that Ale keeps playing well, I see no logic in picking Quagliarella or Rossi.
So what if they're younger? They're not better players and if they're not having better seasons than Ale, then why should they go to South Africa?
None of them played even 180 minutes (2 full matches) in the qualifiers, so it's not like they contributed with anything to the WC qualification.