That depends on what repositories you have enabled - for the default ones it should be okay, but with extras-testing and extras-devel I suspect it'll be rather low.
Anyway, from your other message, it appears you're missing the /var/lib/apt/lists/ directory, so I'd try just creating that (as root - "mkdir /var/lib/apt/lists") and seeing whether that fixes your issue or not. If it works okay, then just double-check the free rootfs space again after updating. Otherwise you'll most likely need to look into freeing up some space.
# apt-get update E: Lists directory /var/lib/apt/lists/partial is missing. E: Could not get lock /var/lib/dpkg/lock - open (11 Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?