Despite all the petitions and begging, despite the official announcements that say the game is in development, Capcom STILL hasn't green-lit Megaman Legends 3 yet; they will be releasing a prototype version (read: demo) and will be basing whether they release the full game on how well the prototype version sells. Notice how I said "sells" in that last sentence. This is because they plan to charge for what is essentially a demo, as opposed to giving the demo away for free like most other companies do. This is Capcom's way of seeing how many people really want to buy the game; if it sells well then we get our sequel, if it doesn't then we don't.
Read the announcement by Eguchi Masakazu here at the official Capcom blog.