OK, so BMW seems to be applying a little more consistency with their naming conventions. At least, that's what I'm thinking after reading the latest issue of Motorcyclist magazine and seeing that the original F650GS (i.e. thumper) is not going to be discontinued, but rather renamed the G650GS. Makes sense

So all thumpers are now G series, parallel twins are F, boxers are R, and inline-fours are K (with the notable exception of the K1200LT, which is still the lopsided flying-brick engine).
About the G650GS. I like it! Sure, it won't be as powerful as the F-series, and doesn't have as many bells and whistles. But at $7670 USD, it's considerably cheaper than the F650GS, and even a little bit cheaper than the Suzuki V-Strom 650 ABS. Not a bad deal. Plus, since it's been around a while, most of the bugs have been corrected and there's a big supply of aftermarket goodies for it.
Cheers,
Lucky