Today, Tuesday 21 April 2009, between 8am BST (GMT+1) / 9:00h CEST and app. 1pm BST / 14:00h CEST the Runes of Magic servers are offline for patching.

The full set of patch notes (Version 2.0.5.1833) can already be found in the patch notes forum. You can discuss the changes here.

Edit: Corrected the expected time the servers should be back again.