It will be way more than 10 games. Very few games are above 1.3GB, Patapon 2 is only 300mb, while Resistance R is about 1.3gb. You can also get extra space through memory stick micro, for £20 you can get an 8GB stick
MGS PW is a proper MGS game, as opposed to PO, it is directed by Kojima, made my the main MGS 4 team, and it is a proper sequel to MGS 3. It will be a reason to get a PSP
Loads of teenagers have iPhones, how do they pay for stuff on that? Anyway, chances are Sony will add PSN cards soon, they would be mad not too.
Most people know that the PSP is slightly too large to fit into a pocket, and making it even smaller and lighter is a great plus. And the added bonus of not having to bring all those UMDs with you makes things a lot easier, and the extra battery life will be good. From Sony's perspective it will also boost the profits that they make on each on PSP, and more importantly, for games like Gran Turismo and MS Arctic Edge, they get 2x the revenue on all downloaded games as gamestop do not get their cut