When (not if) 5e arrives, I'll judge it on its own merits. If I like it, and I suspect I will, then I'll move to it.
I enjoyed BECMI D&D. Great game. I got many years of gaming pleasure out of it.
I enjoyed (some of) 2e. Was it a better game than BECMI? Not in my opinion. However, it was a change. I'd been playing BECMI D&D for 10 years, so the more story-driven approach of 2e... and the fantastic campaign worlds... was great.
I enjoyed 3e (and 3.5e). Fantastic version - it refreshed a massive amount of game mechanics that were starting to get stale. Fascinating amounts of detail and complexity in PC and monster design. Incredible flexibility.
I currently enjoy 4e. After 8 years of 3e, I desperately needed something to make the game more simple, streamlined, and balanced. I'm a huge fan of skill challenges, minions, and the broader "sweet spot" of play experience (previous versions worked best at PC levels 4-9, whereas I feel comfortable running any 4e game of levels 1-20).
...and I expect that I'll enjoy 5e when it comes out, too. It'll probably improve on some things that I find frustrating in 4e. But more importantly, it will provide a change. Life is too short to tattoo "1e [or 2e, or 3e or 4e] FOREVER!" on your shoulder.
8 years is the current average length of a marriage, in the real world. If you can get 5-8 years out of a gaming version, you're doing really well. And you've spent a whole lot less time and money than being married, as well. And... at the end of that particular version... you get to start flirting with a fresh, nubile new D&D version.
So... make mine: "D&D [all versions] FOREVER!"