As for remote - the iPad is a rather large device. The idea of a remote is to be small and ultra-portable. I doubt too many people would use it but still there is no excuse to not have an iPad version.
iDisk - If apple thought enough about creating one for the iPhone, surely an iPad version should have been released. Perhaps they have realised that the iDisk app has not recieved many downloads and so leave it to other apps to do the same job.
Apple Store - It was just released and is not even available outside the US store so we will have to wait and see. We have a web browser which can view full websites with ease, including the store, and so an iPad version isn't really needed.