Considering the 970 is not even a year old, I would not worry about a new version till there is something about it from tech news reports. Why bother with guesses? There is not likely to be much performance differences in real world use anyway if you are looking for a new drive. If you need a new drive, get the 970. If you just want a new drive, wait till you hear about the next version.
Announcing up-coming products too early is a good way to ruin a company, losing sales while people wait to get the next version.