Are you using wireless? If so it might be a connection issue and you may want to plug it up?

Most games I have picked up have downloaded and installed instantly, but others like Strike Wing took close to 45 min of the download bar not moving. You might need to just let it sit.

I'm not 100% sure, but if you're playing games at the same time I don't think games will download; and if you're prioritizing Bluetooth over Wifi (for your controller sake) that could be slowing it down too.