Many federations are organizing their teams for the 2010 Olympiad (Khanty-Mansiysk) which will take place September 19th until October 4th. FIDE has recently released an announcement of important details. Federations should begin preparing to meet various deadlines to avoid any complications later.
In 2008, there were a lot of controversies surrounding visas. Many federations (particularly from Africa) were denied visas for a variety of reasons. There was the thought that it was because federations had applied late. While that was true in at least one case, it was not true in most. There were a couple of nations cited for arrears in fees and FIDE threatened to cancel their accommodations.
Thus, make sure there is enough time so that if complications arise, adjustments can be made. Also note that there are deadlines for clearing arrears with FIDE.