One feature I really like about RDX is the fact that it will time boss encounters automatically for you (when combat is engaged and when the boss is dead).
Given the architecture of BigWigs I think that this would be a very easy module to add and very helpful for tracking raid composition, strategy refinements, etc. On top of just calculating DPS I find attempt time very helpful in refining strats/charting progress.
Just have a small window with the boss name and a stopwatch-like timer interface. Maybe a start/stop/reset button too. I'd love to have this.