So, I do believe there are a huge mass of Ps2 owners that will buy only the next Sony, want to play those IP's, aren't interested in an xbox, and will wait until PS3 drops into their pricerange.
This is the interesting part. I agree with the overall thought process and in a typical console generation, I believe this formula/theory would still work. This gen though, Sony threw the formula away. This in and of itself isn't a big issue as long as all other players involved follow suit on the new formula adopted by Sony. As we know though, they haven't.
As it sits currently, it is a race against the clock for Sony. The same userbase that bought ps1+ps2 did so at a significantly different price point than what ps3 is currently selling for. These same people will/would likely do the same at a similar pricepoint as they already paid previously, but when ps3 will hit this point is an unknown. At the same time they are hoping to maintain their ps1+ps2 userbase, they must also retain their ps1+ps2 3rd party support.
Exclusivity has already been tossed aside for the vast majority of these 3rd party developers. This in and of itself again isn't a big deal. But again, the competition is not following the same formula as Sony this gen.
I think they will lose a significant share of these ps2 users to xb360 or Wii this gen simply due to time. These users will only wait for affordability so long on their platform of choice and every day that goes by, another familiar ps2 game is announced or shipping on xb360 or Wii which are much more affordable. As this shift continues there will come a point of no return for developer support, mass media and market acceptance, and general mindshare.
Of course, the other players in this game would have to capitalize on this opportunity and thus far, both have dragged their feet. (Nintendo with manufacturing capacity, and MS with delayed (and psuedo reversed) price drops) With each mistake these competitors make it seems Sony feels a duty to mirror their own, but they still have an opportunity at this point to regain their dominance.
Brand loyalty at this point I feel still does exist and there are a lot of ps1+ps2 users out there. They just need to adjust their price in time to capture their ps1+ps2 users before they get the itch to switch to a nextgen box. Killer software announced/demonstrated can act as an anti-itch creame for them but must be shown soon. With E3 right around the corner, I expect Sony to come out swinging for the fences. If they outscore Nintendo and MS, (who will also be looking to swing for the fences) then they can delay this itch to switch. Whether they can delay it long enough is another question.