they're doing pretty good with lag, max 7 seconds and it went down in one.
I saw 20 seconds at one point on the IRC. It didn't last long though.
[00:36] <gribble> BTCUSD ticker | Best bid: 91.55000, Best ask: 92.00000, Bid-ask spread: 0.45000, Last trade: 92.00000, 24 hour volume: 150121.79836125, 24 hour low: 84.43689, 24 hour high: 102.00000, 24 hour vwap: 94.43328
[00:38] <gribble> MtGox lag is 19.233831 seconds.
[00:39] <gribble> MtGox lag is 20.502757 seconds.
[00:39] <gribble> MtGox lag is 1.515664 seconds.
[00:39] <gribble> BTCUSD ticker | Best bid: 89.16000, Best ask: 89.30000, Bid-ask spread: 0.14000, Last trade: 89.30000, 24 hour volume: 154654.33890230, 24 hour low: 84.43689, 24 hour high: 102.00000, 24 hour vwap: 94.30519
[00:44] <gribble> BTCUSD ticker | Best bid: 89.00000, Best ask: 90.00000, Bid-ask spread: 1.00000, Last trade: 90.00000, 24 hour volume: 157349.67463144, 24 hour low: 84.43689, 24 hour high: 102.00000, 24 hour vwap: 94.20760