Sony could have easily won me over with the PS4 with how outraged I was in the very beginning about the Xbox One. They failed to, and I think they will fail to with many more gamers. If the price is $50-$100 less, Microsoft will have a hard time keeping up, and if it's more than $100, Sony just might be able to really kick butt, even if it's not overly impressive, because at least it will be cheaper and less intrusive.
Anyway, it's way too early to tell. A thousand different things could happen to change the scope of the console wars and I'm certainly not going to place any bets any time soon.
Edit: Just heard it's $400. Plus to Sony. It's charging for online gaming, though. Minus to Sony, since that was a major selling point with the PS3 for many. No DRM, plus to Sony. Still don't think it's the nail in the coffin. Wii U is significantly cheaper with free online and still not likely to shine.