Ok... all that means is you've already got them, or it happened during that long lull while it was 'connecting'.
Check the Steam News page:
Half-Life 2: Deathmatch, Source SDK, and Source Engine updates are available and will be applied automatically when Steam is restarted.
A Source Engine update is available and will be applied automatically when Steam is restarted.
A Half-Life 2 update has been released via Steam. Please restart Steam to apply the update.
Maybe not all that obvious all the time, but as you can see it only happens when you restart Steam.