I like the pose a lot. But if you're looking for suggestions, maybe raise his head a little to show his eyes, or one eye? The 'determined eyes' are kind of Syaoran's characteristic, that might help it look more 'determined' and not be mistaken for 'defeated' in that pose. *shrugs* Well, I don't know.. might be something to try. Depends on what else you put around it, also, I think.
What were you thinking, like two superimposed pictures of Sakura & Syaoran? Or like a collage-type thing?
In any case, I think the idea's cool. Look forward to seeing the end result.