According to a friend, there are plans by one MAJOR 3rd party to do just this, exploit the backwards compatability and in turn hold off on PS3 developement until the market saturates and matures. It's too expesnsive and risky according to the source. This same company has on the other hand put out a NUMBER of X360 titles that actually look next gen.
I wouldn't be surprised if this was a branding movement across the boards, not just for this one company. On a positive note for SOny fans, they are still going ahead with a major title for the system, even though it isnt looking as hot as once implied.