I'm not into handheld gaming anymore (last handheld I bought was a PC Engine GT over 15 years ago), but I'm thinking of getting a PSP as a peripheral for my PS3 along with the other multi-media stuff it can do. I'd probably get some games for it (I already own MGS: PO as it was included in MGS collection), but I wouldn't use it primarily as a gaming machine.
So I kind of agree, PS3 sales should help PSP HW sales as they have some cool connectivity features, but it won't necessarily help software sales in a big way.







