It doesn't matter. The PSP2 will sell way, way, way, way (... back in a minute ...) way, way, way more than the Pandora. This is an acceptable truth. But it will serve a different group of people. The Pandora is an open platform with easy access to development; the PSP (and subsequent PSP2) is not.
If we assume the PSP2 will outperform the Pandora in every respect, it still won't be suitable to the group of people for whom the Pandora is targeted. This group is still large, and there is no fear of the PSP2 usurping the position of geek-toy-extreme from the Pandora for these people.
On the other hand, if we assume the PSP2 specs are below that of the Pandora, it still changes nothing: the overlap of Sony vs Pandora fans is sufficiently small that those sitting on the fence, even if swayed one way or the other, should not make that big of a mark in any sort of sales figures.
These are just estimates, simple "facts" and "figures" pulled out of my nether regions, but it makes logical sense to me. We can debate the PSP2 all we want, but at the end of the day, I'm fairly certain it won't matter.