In a short while (next 30 minutes or so), plugins.svn.wordpress.org will undergo a DNS change as part of a datacenter migration. The TTLs are low, so this should only take a few minutes.
Nothing will go down, but the SVN repository will become temporarily read-only. If you try to commit code during this time, you’ll receive an maintenance message pointing you here. Plugin pages and downloads will not be affected.
Also, the associated Trac at plugins.trac.wordpress.org will be taken offline (for up to an hour) while it is migrated and re-synced.