Rumors of a new PSP were hot and thick like southern style gravy before Sony began its most recent E3 press briefing, but as you might have noted, nothing as pyrotechnic as a new handheld was unveiled. Regardless, the non-announcement hasn't spelled the end to new hardware whispers. And the fact that a Japanese retailer (via MTV Multiplayer) has listed a new PSP handheld isn't helping matters.
Retailer Geo has listed a PSP-4000 model for 2010, providing no detail. But one can gather from the name that the device will use UMDs, perhaps signaling that the PSPGo all-digital revolution is beginning to end with a whimper despite recent pushes.
It's possible that Geo has it wrong--the retailer might have listed the device in some sort of horrible error. As Siliconera notes, Geo also has the Nintendo 3DS pegged as a 2010-bound device, which might or might not be incorrect. Reggie Fils-Aime, at least, doesn't believe the Nintendo handheld will hit stands until 2011. There's also the fact that Geo has Pokemon: Black/White's release date apparently wrong, too.
Looking for a new PSP? I'm currently in Tennessee right now and enjoying my iPad on the road as opposed to my PSPgo. Funny story: I actually forgot that I even owned that PSPgo until I started packing boxes in preparation for my current cross-country adventure. Considering this, I don't think a PSP-4000 is in my future.