It's not "driver issues", it's the fact that R9 290 was supposed to compete against GTX 770, now with the recent price cuts it will compete GTX 780.
The new drivers will increase clock speeds apparently and reviewers have been asked to re-run their benches with the new drivers for R9 290 (when they get the new drivers)
The 280X already does a fine job against the 770. It would be silly for AMD to think that 7xx prices wouldn't adjust to the new competitive reality.