Four-digit weekly sales without a motive is disturbing - four-digit sales with price in mind and a clear roadmap where price reductions will follow another.
I don't get your point there : are you saying that one factor is that the people are anticipating a price drop ? If so, nothing has been announced yet ... AFAIK it could occur in 2008. Sony 's position will get more and more difficult, because there are (maybe) 6-9 more monthes left.
Also, as long as PS2 is still selling quite well (it is), I'm not too sure many publishers are all that worried yet - because it shows that there's still a market that's potentially interested in seeing successful games/franchises evolve on the PS3. Price is one factor - another factor is the very strong PS2. Less people feel inclined to 'upgrade' with a very much used and supported PS2 at the moment. The time will come though when the price [of the PS3] is right and the software is there. That time will come. How well it will do, we'll see about that when it gets there.
IMO, you are milking apples and pears there : there are tens of games in development for PS3. Whatever the sales are on PS2, if PS3's games bomb due to userbase, why should they maintain other developments on this platform ?