Get it now... It's 100% worth it. Plus 7.1 is coming out in a matter of weeks (hopefully). You will not be sorry...
Yes, this. Just get it and enjoy it. Period. Chasing the perfect timing to buy electronics is a losers game. Sure, buying them on release day is awesome but it's still old in six months, using tablet logistics. No worries.
You'll get many years out of an Air. I know I will out of mine.