Not sure if these are known yet - but what are we looking at for the size of games?
Do we know how big the PSVita cards are?
If I get an 8GB card, and the games are 4GB each... that's not going to work so well.
You don't have to buy Vita games off of PSN if you don't want to. You can buy them retail, well except for the PSN exclusives.
As for your question launch Vita game cards are 2-4GB in size.
Why doesn't Sony make publishers include a digital with the retail copies of the game like they do with blu-ray movies
Because you can keep the download copy and trade in the game card copy?