After getting over the initial shock, I like this decision. This is a bold strategic move to gain market share of the existing demographic that favors PoW, which can then be transitioned to PPCoin in the future.
Primecoin will be analogous to Apple releasing the iPod (an mp3 player superior to other mp3 players at the time), but then blowing everyone out of the water with the iPhone (PPC) afterwards. Recognizing consumer behavior and innovation trends takes a lot of strategic foresight, and I'm happy Sunny has recognized this.
The one caveat I would have is that PPCoin still needs to be maintained/upgraded in parallel with Primecoin to ensure consumer trust. Many of us who support PPC do have financial stakes in it, and it would be unwise to simply put us on the shelf for the foreseeable future and abandon aggressive development. We're 3rd or 4th in market cap, and it's going to take continued efforts to gain on Litecoin.
I also think it's time for Sunny to recruit an expanded development team that can oversee the umbrella portfolio of the P coins...Prime and Peer. Apple has a portfolio of products (iPod, desktop computers, iPhones) with very siloed development, and I think that approach could work beautifully here. Dream big Sunny!