Well 35m should be possible by the end of the year (2m in each region in Dec is plausible) - 40m by March / April maybe? 50m+ by the end of 2007 !!
Maybe, but that remains to be seen. I don't think it has the staying power.
Once PSP comes down in price there really is no comparison, that's what is continuing to hold PSP back, the refusal to drop the price. MP3, Video, and games...As opposed to just games...
It would be a feat if it could sell more than PS2, but it's not the same thing. They already lowered the price of the DS to 130 dollars, much more affordable than the PS2 console was at this point in life cycle.
Besides, it doesn't have the best software sales, only in Japan. Still, maybe they will.