So I've been watching for the past couple of days. I've noticed slush's pool go from 700 GHash/sec to over 860 GHash/sec in just a couple of days.
I've also been watching the hash distribution pie chart on Bitcoin Watch: http://www.bitcoinwatch.com/
It seemed pretty constant over a couple days, each pool was growing proportionally to the other so that the overall distribution didn't change much.
Discussion: Where the hell did all that "Other" come from? I could have sworn last night "Other" was ~15% of the pie. Now it looks like ~45%. Anyone have ideas what could have happened? Did some hacker just unleash a massive botnet?