I quite like the first set of logos with "wiki" and "forum" but don't know if that detracts from the simple cleanliness of the original. Having asked the missus she says they read like "Bio forum powered" which doesn't work, and I'm inclined to agree in that respect.
As far as colours go, I've got a terrible sense of style but anything orange/yellow/green fits the theme. The missus likes the dark green/light green combo, I like the orange/green the most I think. Whichever choice should have the orange oil drop over the i of Bio, which is a touch in the original that I really liked very much.
Not sure how I feel about the smaller "owered" leaving a gap between the top and bottom rows. I'm not a graphical designer so feel a bit at sea on layout aesthetics!
I also really like the favicon interlinked b and p idea, would have to scale it to 16x16 to see how it compares to just an oil drop.