Microsoft has taken the next big step towards its goal of bringing user-created games to Xbox Live Arcade. The software behemoth today hung out an “open” sign on its Community Games for Xbox Live beta, allowing small developers enrolled in the XNA Creators Club to share, review, and download each others’ games via Xbox Live Arcade.

Currently, only Creators Club members with “Premium” accounts — which cost $99 a year — can access the service, but MS plans to make top-voted Community games available for download by John Q. Public in the fall.

The Creators Club and Community games are the next stage of Microsoft’s XNA initiative, which saw the introduction of XNA Game Studio 2.0 — a suite of tools for creating Xbox 360 and Windows games — earlier this year. The free software package is intended to simplify the development process and encourage upstarts to make Xbox 360 their platform of choice. It includes a variety of tutorials and samples, which MS added to today with the introduction of a free Role-Playing Game Starter Kit.

News of today’s beta launch comes in the wake of our earlier post on MS’s intention to “leapfrog” PSN and WiiWare with the help of indie developers.