In case you were wondering, my 3,514 entries (and 6,800 comments) with accompanying pics came to a bit over 11mb. I haven't had a chance to play with the program much (I wish it opened up in a more LJ-like interface), it will be interesting (I'm pretty sure it has that functionality) to see how many words that represents.
It is nice to have 8 2/3rd years of my bitherings safely on a HD here, however. I may also look into one of those "mirroring" programs that would let me port out my LJ off into one of the clones (heck, I'm user #28 over on DeadJournal, but only have four posts over there!) ... but I'm (obviously) hoping that LJ doesn't go away.