I hadn't noticed the "Uploads" section previously, so I hadn't stalked my photos. I just let it happen in the background. Now that I've got a video uploading I have an observation: the uploads section sucks, at least for big files. It doesn't have any sort of progress indicator. If there was a % on there somewhere, that would be great, otherwise the queue doesn't do an awful lot of good except to tell you that you have a queue.
Oh, it finished! It was a minute clip, about 200 megs, and it took 6 or 7 minutes to upload over wifi. No problems to report. Had I not been stalking the download dialog for the purpose of this test it would have been a better experience, quietly in the background. But at (at least) 6 minutes a pop, I can see how several videos would tie up your skydrive sync for a while. My takeaway is, I'm turning off video uploading. Should I make a video, I'll plug it in to my pc.
In general, I've been very disappointed in the Windows 8 sync app (coming from Zune, which I still think is the unsung best-ever media platform), but they did one thing right--that app will automatically drop everything in your skydrive folder if you have it installed so it ends up backed up on the cloud. (Apparently I had the foresight to set my skydrive photos as my default folder in my "Photos" collection)