Updates and corrections for BA:

Miles are now called Avios (optional)
First gives +500% the tier points of economy (210 vs. 35 for most long-hauls.
Business is +300%
Qualification and requalification are the same thresholds. One can get BA Gold from Europe excluding UK/IE with 800TPs until 1 March 2012. After this anyone who has achieved gold at the old rate can renew it up to twice at 800. After that and for everyone else it goes up to 1500TPs.
Golds get 100% mileage bonus on BA marketed flights.
One-way international one-class upgrades are available for between 4500 Avios and 100000 Avios depending on route and which class you want to upgrade to. They are also available on IB and AA flights although only from the most expensive fare buckets.
There is no lounge access available if not flying oneworld.