In a post about the new MS Office, Runar mentions Pollock:

Previously there has been focus on how Pollock will make sure the GUI looks good, by ensuring screen updates do cause flickering. Pollock definitely also need to have focus on drawing speed.

Pollock is not really even in beta yet. We are closing in on the first supported release (see the roadmap here) - and here's the thing - don't worry about the performance issues. Our developers have been focused on the "heavy lifting" thus far, and, even before they get to serious optimization (and optimization is a large part of the internal roadmap), they know of a number of things which, when optimized, will make performance improve a lot.

We don't follow the theory of premature optimization here - we want to get the big things right before we focus on the rest of it. Rest assured, Pollock will be fast when it's ready to walk out the door.