I once swore I would never program in client-side JavaScript again. This was about the time that IE was first starting to take over the world, and Microsoft were promoting rubbish like JScript. Actually I swore a lot back then, but now we have a new age of JavaScript enlightenment, with Ajax, Web 2.0 and FireFox brightening the JavaScript world. Bless you, FireFox.
Of course, I never really stopped writing client-side JavaScript. It's unavoidable. Lately I'm working on a framework to query imported XML objects, in a xpath-like way. Which, it turns out is complicated enough to require some debugging effort. But how much does it suck to have to alert()nine-hundred times? I can tell you it sucks a lot. Haven't things improved any more than that in all these years?
Well, things have improved. A lot. I just discovered a little miracle called FireBug and the only swearing I've done since installing it is of the "Holy $!@ this is good!" variety. More evidence that the future of client-side JavaScript is looking very bright indeed.