Business side, Percona shoots two birds with one stone: NoSQL, and Fractal Tree Index patent.
Technology side, I followed Fractal Tree Index technology for a while. FT index is a B tree variation, claiming to be magnitude faster on insert and deletion than B tree, and it is one of the few approaching the lower bounds I/O complexity. This algorithm boosts Toku MySQL storage engine performance over others by a wide margin and so on MongoDB. FT is also used as both user space and kernel filesystem. Papers show quite compelling results on meta data intensive micro benchmarks.
What would happen to these interesting FT extensions is unknown after this acquisition, but they get my best wishes.