I have the Sony Google TV thing.
I initially bought it as a curio, but as a device it is actually quite nice. Having it separate from the TV means you can pretty much upgrade when you want.
With that said and with this article in mind, it looks like manufacturers want to lock us into a specific life span for their tv's.
This is a bit pish - I have a telly over ten years in age that works perfectly. So why should I be forced into upgrading the dumb bit just to get more features from the smart bit?