Hi Kevin,
If you install apps from your PC to the phone, you won't be informed of updates. If you install them via the official Android Market (which is already on your phone when you get it), it tracks and notifies you of updates. As many Android programs are updated regularly I'd recommend installing most, if not all apps and games via the market.
It'll make more sense when you see it for yourself. Or, when your wife does anyway hehe. Oh, you are so going to suffer watching her using the Desire
Cheers,
Leaston