Last check it was a 15 minute lag time for orders to be processed. At this point I think Mt.Gox should halt trading, it dangerous to the system if you can't process orders in a reasonable time frame, and nor can users cancel their orders, you're just getting a dam behind which is a ever increasing number of panicing sellers/buyers who have no accurate information and yet every decision they make only exacerbates the problem.
This is actually a good point. Choppy market is one thing but at some point trades were being reported out of order on a half hour span.
The other consideration is that halting trading causes panic. A damned if you do, damned if you don't scenario.