It was announced back in 2010 that Champions Online would be moving to a free-to-play model, but that has now been dated: JANUARY 25TH IS THE DATE. Needless to say, you can keep subscribing to unlock loads of the content that will now be available via the "C-Store", or you can play for free and buy various content packs with micro-cash. Here's an FAQ that may answer and questions you might have. I link to that because can't answer them, not accurately anyway, but if you do want to ask questions in the comments below I'll have a wild stab at answering them when I wake up in the morning. Or I might just forget, or idly blog links to Minecraft texture packs instead. Anyway, you can already play some of Champions for free, because there is a trial mode thing, or "demo". Hooray!
You will remember, of course, that Champions Online wasn't as much fun as City Of Heroes, which was a shame, but that's life, eh?