Almost similar to how gmail does it, upload images, click send, and it waits to see if they are uploaded before sending.

Could be a nice feature here, instead of "skipping" the upload when submitting.

So,

I upload 10 images, half of them have uploaded, I click "Post" or "Save Changes" and the post waits until they are all uploaded before posting.

I'd assume most of the code is already present for this as Gallery makes you wait :)