Edge, a new HTML 5 animation tool from Adobe. Anyone who is interested in creating simple animations for website, I recommend download this beta and giving it a test drive.
In Macworld's post here, they give us four things to watch out for. One point they mentioned is that this will not replace Flash. My take: Not yet.
Also, it's geared towards mobile. However, it doesn't mean if you're creative, you can't use it for anything else.
Give it a try. It's free anyway, for now.