They might be playing in on the "Wii Shortage" fear. If my best buy is any indication that shortage is done...
Does anybody know the initial numbers from the DS lite? Probably the best way to guess at this.
Edit: The DSiware launch games have been announced, Warioware: Snapped, Bird and Beans (PYORO!), and Art style Aquia. No pricing, but IGN (Where I got the news) suspects the same as Japan, which would put Warioware and Aquia at 500, and pyoro at 200. The opera browser is also planned for release, and should be free.
This isn't happening on Sunday though, I'd guess Monday.