IF they get announced / developed, I seriously doubt Bioware is involved. They're currently working full steam ahead on Jade Empire and Dragon Age (which looks absolutely AWESOME, btw), somehow I doubt they have guys left over to do BG3 and / or NWN2.
Furthermore, Bioware has repeatedly stated that they have no real desire anymore to work with the D&D license, that they would much rather work on their own IP, such as Dragon Age (Jade Empire doesn't count I think, since it's probably at least half owned by MS in order to be released on the BillBox.)
However, since both of the licenses probably are in the hands of Infofuck, I have no doubt whatsoever that they would create sequels that suck plentifully, just to rape more cash out of the franchise.
I mean, seriously. Baldur's Gate 3?? What the fuck is left to tell in that story? Son of Bhaal becomes a God. The End. Why bother calling it Baldur's Gate 3, since there's nowhere you can go with the story, except for name recognition and thus hauling in cash.
Bah, Infogrames makes me fucking sick to my stomach. Why do the fucking shittiest publishers always wind up as the biggest ones in the industry? Are we gamers really that fucking stupid that we keep buying their shit? Apparently so.