That said, I just want to point out what it'll look like.
First, screenshots should be posted quiet regularly to show that the work is being done. That doesn't necessarily mean that what's shown will for sure be the same in-game. Plenty of things may happen between the alpha, beta, and release phases of development.
Second, there are some things that I won't be able to show all that easily (new advancements in scripting for example). I could show GUI/HUD updates, but to what you're character can do in-game would have to be video. That said, those will most likely be few and far between.
Third, no true demo's will be released until I've gotten far enough along that the alpha/beta team says it's good. BUT, there will be map previews, things that you as the community will be able to enjoy.
Look forward to some screenshots soon and stay tuned!