As far as I've been able to find, there's no "batch copy" or mass move per se. Sadly, it's one photo at a time (I have almost 40 gigs up there now so I get your point.).
I guess the part I didn't explain is that this is primarily a photo sharing site (obviously, I guess). It is secondarily a backup site and that's the way I use it. All my stuff is on a rack-mount RAID 5 Windows server in my home office. It's all backed up twice weekly to external hard drives and rotated between a fireproof/waterproof safe in my home and the same type safe at the home of my best friend (we do reciprocity on the backups).
I guess what I'm trying to stress is that I'm covered 6 ways from Sunday... PLUS ONE. SmugMug is my backup of last resort. Quite honestly, it would take a helluva catastophe to make me have to go up there and get everything. I dare say if I ever have that problem, I will have much bigger fish to fry long before I'm worrying about my photos. I'll know they're safe and I'll get to them when I can, if that makes sense.
While all this "cloud stuff" is fine and dandy, nothing beats a good local backup strategy. It's not hard. It's just good ole common sense. Copy it all to a QUALITY external HD and put it somewhere safe away from your home. Stick it in your desk drawer at work if you have to. Get in a habit of doing it with two drives and keep one at home UNPLUGGED from your computer when you're not actually backing up to it. Rotate them every week or two or whatever your photo adding volume dictates and makes sense to you.
Treat your backups as backups. Never work on the photos on your backup drive. Treat them as masters. If you need to revert to them for a disaster or just to recover a file you inadvertently deleted a week ago, copy it from your backup to your working PC first.
My backup policy is actually much more complicated than just rotating 2 drives weekly. I retain month-ends, quarter-ends and year-ends too, but that's mostly because of my business concerns. The photos are just along for the ride, if you will.
Why do I make that point? Because what if you deleted a photo 6 months ago or more importantly an entire directory and didn't even realize it until today and were on a two-week rotation? Ooops! For most consumers, I have to believe that SmugMug is enough protection for that type of situation. You can always go there and get it/them. I never delete anything from SmugMug. Never. Anything. Even my throw aways go up there FIRST. It's just a habit and a workflow and getting use to it.
OK, I'm babbling on but I hope this helps. Get a SmugMug account and use it primarily as a sharing site but know that it's there in case of a catastrophy, and if you use SmugMug, a program called "SmugUp" will be your best friend.