It's only available for US residents and the micro-console hasn't been mentioned. Streamable game titles can be bought or rented.
The monthly subscription rate will adjust according to how long a term you sign up for, with the first 25,000 users getting their first three months waved off. That includes access to OnLive's friends functionality, spectating, gamertags, free demos and more.
To actually play full retail games you'll need to spend more either buying or renting them, as the monthly rate doesn't include the catalogue. The OnLive micro-console, which plugs into TVs to 'replace' home consoles, hasn't been slapped with a date yet.
Will OnLive be rolling out to the rest of the world? CEO Perlman says details on such a matter will be unveiled later in the year - obviously they want the US to launch okay first. OnLive's launch will be close to that of E3 this year, likely to boost awareness.
Check out some footage below of OnLive at last year's GDC event.