Actually, I've only heard rumors about a movie.. that's it to date. Although the "Save Farscape" and similar campaigns have now raised almost $400,000 to date.
As for why it was cancelled, that was Vivendi's decision (the same people that brought you the cancellation of Babylon 5: Into The Fire, a cutting edge space simulation game set in the Babylon 5 universe that would've been an awesome game; cut at 85% project completion). Vivendi owns SciFi Channel, and they've been losing money for years. Vivendi quoted low numbers and rising costs for the cancellation of Farscape.. for all the details on it, head over to "Save Farscape" and get all the details, the original cancellation notice, and the "Save Farscape" rebuttal to that notice with examples as to why Vivendi was blowing smoke.