Sony should take a page out of Nintendo's book and start calling Playstation something else. Maybe they could call it nothing, like Led Zeppelin's #4, or The Beatles White Album. They could just ship a plain, black machine, with no markings of any kind on it, and whatever name caught on amongst us gamers, that would be what we called it. At the very least, just stop counting up, like Final Fantasy. Are we going to see a Playstation XIV someday? Hope not!
Maybe they could drop the 'station' part. Why not call it Playworld? Playparty? Playgalaxy? Give the system a name that tells us all something about it's character. How about Playdom? Oooo... I kind of like that one. They could make it all transparent and call it Sony's Skeleton. Or drop the 'Play' part and call it Sony's Sunstation. Sony's Superstation. Sony's Samuraistation...
It'll be a cold day in hell when Sony (or Microsoft for that matter) abandon their console brand name. Nintendo has the advantage that their company name is synonymous with video games. It doesn't matter what they call their hardware, the Nintendo name alone communicates volumes to consumers.
That said, I'm with you on the numbering thing. Assuming there is a future iteration of the PlayStation or Xbox, I'd prefer something other than a simple numeral increase.
For the next gen, I predict "PlayStation 360" and "Xbox 3".
@ Tim- That's pretty funny.