A reprint of the 3.5E PHB would be a good move, updated with errata would be brilliant because it would add value to folks that already have a 3.5E PHB.
I've spoken to a lot of folks that still play 3.5E, or even started playing since the release of 4E. The biggest issue they have is that they don't have access to a ready supply of reasonably priced 3.5E PHBs. And that doesn't surprise me, you only need one DMG/MM per game group, but one PHB per player is desirable. It's a pain for new 3.5E D&D players.
PF is great, it really is, but as mentioned before it isn't D&D. It is my D&D in all but name, but it doesn't have the D&D brand and that is important to a lot of folks. Also while PF might be popular, it doesn't mean everyone knows about it, about half the folks I talk to here buying my excess D&D books haven't heard of PF (although they'll look into it as a possible new version for their game group after I show them the core rulebook). Still most game leaders (although not necessarily full time DMs) have a huge investment in 3.5E D&D books and are still looking to complete their collection and want to give it value by playing it.
You could use the electronic versions or the printed SRD versions, but a lot of folks still prefer a nice full color hardcover physical book.
WotC has an issue with the D&D brand, it's loosing value due to 4E loosing a lot of fans/sales to PF. WotC might be forced to do everything in their power to keep as many D&D fans as possible while they scramble at a 5E edition that might return D&D to it's former glory...