I'll post updates on the official Mediamax blog about upload delays as comments on this entry, rather than a new one each time.
You can find it from the 'errors list' link at the side.
This has been posted today. See:
UPDATE: We're back up to normal speeds, thank you for your patience!
Just a quick note to our users that there's a brief upload delay so files won't immediately appear as per normal.
We should be caught up shortly and will update this post when we're caught up again.
You can't leave comments on the official blog, so leave them here.