Historically, once the new version has been announced, there are deals that typically go "buy X2 now, get x3 for free when it's released." So that's the deal you'd be waiting for. I kinda think that's a safe option as then you get two versions, one of which may be more stable on your system than the other. But no garuntee this deal will show up.
Personally, I'd wait. But that's an easy choice because I'm too busy to make music right now (planning a wedding) and don't have the cash (paying for a wedding). It depends on how patient you are and your financial situation (ie buy X2 now then buy X3 in a few months too - which is not a compulsory purchase, of course).