In the past, the WOTC boards have always been bumpy for a few days following an upgrade/change. If you ask somebody there, they'll probably claim that the "cache" is being refilled.
On other random days in the past, exceptional slowness seems to be an indication that somebody's currently monkeying with the server or tweaking some aspect of the message board software. (there's usually something new or different after a slow day, like more avatars or graemlins for example).
Give it a few more days and it should be back to normal (which means, occasionally slow anyway.... but not as much as now).