So... "Syaoran" on his trip to Clow was only for supposedly seven days, during Princess Sakura's purification. A pricey trip for seven days, and has to return home? Plus, he has the choice to do... nothing? There was no specifity what that choice really is.

Now about that choice, I wonder about the Dimensional Witches message of what happens after those seven days, she says the choice is Syaoran's. Considering that the Queen and Sakura K. already foresaw or predicted that Syaoran will be Sakura's "Number one", looks like this is fate/destiny, so poor Syaoran. No choice there.

I wonder if Clamp will show us Syaoran's home world... I kinda hope so.