I love this. This was the main thing I wanted to use from Mountain Lion, and I thought that the only two ways to use it would be to use Mountain Lion beta now, which costs money every year, or wait for Mountain Lion to come out and update to it. Surprise, Surprise! iMessage beta is available now for Lion as a free download from Apple's site. I am starting this thread so everyone can place their opinions on it, share why they like it, why they don't like it, or have one central thread to talk about glitches and help each other out. I think I have made it obvious where I stand, I LOVE IT! And the only glitch I have found so far is when I put it in full screen mode, I can see that textured gray background behind it...on each side of it. Though I'm fine with this.