1.5 is on the horizon and I must say I'm pretty damn excited about finally getting some natural ice. I've been building things out of ice for a while now, but I've always missed the realism of being able to freeze ice out of water. I can lava-mold and make some cool obsidian things, but no ice-molding so far. Until 1.5.
The rain looks pretty good too. My only gripe might be the sound. I can't tell if it might get annoying after a while. We'll see. But between powered rails and wonderful thunderstorms, 1.5 is personally a very exciting release. Can't wait!