I know what you mean... I was almost done reading the Dune series before I realized that the author died before he could finish it, and I found the "completion" of the series written by his kid and one of the biggest SF hacks around just damn near unreadable. Then Jordan up and dies on us before he could finish WOT, I'm just glad the guy who's finishing it off has done it justice - there are more than a few spots in book 12 that just send chills down the spine.
I started to get into George RR Martin's work before it became painfully obvious that he's just not interested in moving ahead with that series any more... Serious - check out his website sometime, and see what he says about the next book in that series - one that was supposedly all but complete 5 or 6 years ago. I pretty much refuse to start reading any more "serious" series that aren't already completed anymore.