Slush's pool AND Deepbit are both getting hit big-time, repeatedly, with Distributed Denial of Service attacks!
What gives?
1. target ~65% of aggregate mining pool with hired zomB net DDoS
2. Continue to mine your own 20-50 Ghash minifarm solo
3. Increase personal likelihood of mining whole blocks by factor of 1000
4. Profit
Your probability is based on the difficulty not the current global hash rate. You would need to run #1 long enough (2 weeks) to affect a difficulty decrease so #2 is profitable