Improving the MobileMe interface with the ipad would make almost everyone who owns an ipad buy a subscription to MobileMe, I think.
Imagine if they fully incorporated it into the iwork apps. So you start a Pages document on your ipad, then press an integrated button labeled, "Save to iDisk," which would automatically upload it to your idisk. Then later you go on pages on your mac and press open, and find the document on your idisk, work on it, and save it back to the idisk. Later, you then open Pages on your ipad and press open, and you could access the document you saved from your mac on your idisk.
Its seems simple enough, and would be 100 times better than the current file system they have, which involves emailing, or using a crappy iwork.com beta, or physically syncing with a mac. None could beat simply being able to access and save to idisk from directly within iwork apps.
Come on Apple, get with it and make using MobileMe easy on an iPad!