An ounce of prevention...
Here's how I see it, and consequently, how I think Sony is playing this whole deal. First, you have to dig back to the roots of the Xbox, which lie in WebTV. Some of the execs at Microsoft didn't want a gaming machine as much as they wanted a game-enabled WebTV. They wanted to make a super-duper WebTV which could record shows like Tivo, play games like the PlayStation, and surf the internet like...well...like WebTV. Eventually that idea fell by the wayside, probably due to the final cost of the machine being too far out of reach and too much R&D time to develop the thing. Remember, Microsoft uses a lot standard PC hardware in the Xbox, not custom stuff like Nintendo and Sony.
So what does this have to do with Sony and the PSX? Sony knows that the next Xbox will have the aforementioned Tivo-like features. Sony is also not ready to announce anything in the way of a new console other than they are working on it and it will use lots and lots of processors to do various jobs and will be a thousand times more powerful than the PS2. But if they announce this system, it will take a lot of steam away from Microsoft when they announce specs for the Xbox 2. It will come with these features like recording TV and possibly disc burning, but Sony will already have that machine, so why care? It's sort of like their announcement of the PSP, except this time they actually have something more than a sheet of paper with some proposed specs on it.