Given that the very best research (meaning not available for sale, still in development) solar panels just recently set a new record at (I think) 35% efficient, this leaves lots and lots of room for improvement. If I'm not mistaken, the best ones you can actually buy are about 20% efficient currently.
So, rumor or no, I'm pretty sure that better ones are coming. And after those, even better ones . . . .
I would suggest that when you decide to go solar, you buy the best combination of cost and efficiency you can find, and never look back. Better ones are certain to come on the market shortly after you write the check, no matter when you do it, so don't worry about it, and don't put off buying waiting for those better ones, or you'll never take the plunge.
