The most recent price drop is like a breath of fresh air for anyone who has ever enjoyed a game on a sony console. The drop was long-warranted, perhaps even as long as since when the console was infamously introduced at E3 over 3 years ago.  Frankly I was thrilled that the PS3 slim was announced at the 300 dollar price spot. However, there was one aspect of it that was a complete deal-breaker for me. 
As recently as a week ago I finally obtained my own PS2 (in a straight up trade for the entire Naruto series, which i had gotten on the cheap and never bothered to unwrap). I've loved it so far, especially Odin Sphere. So you would think that I regret the trade now? Not at all. 
The main problem that I had with the PS3 is something that has been maintained, despite consumer dismay. That is the lack of backwards compatability. On its own it only has a bare minimum of games I want that I don't already own on the 360 (Those being Metal Gear Solid 4, Valkyria Chronicles, Uncharted and perhaps the Ninja Gaiden remakes). If the console at this 300 dollar price had backwards compatability, I wouldn't be here writing this blog post (my first in a few months). Instead I'd be banging on the doors at Target begging them to let me in when the sliding doors were only feet away (i can be kind of a loon sometimes).  
So, in summary:  
                               Playstation 3 worth 300 dollars for people who do own PS2s and not 360s? YES  
                                     Playstation 3 worth 300 dollars for people who do own PS2s and 360's? No
                   Playstation 3 worth 300 dollars for people who don't own PS2s and do own 360s? NOT NEARLY 
If/When Sony does release a BC PS3 at 300 dollars, I'll be there day one. Until then, I'll be happy with my PS2 (and Wii, DS, PSP, and 360)