Now that Amazon has purchased Goodreads and intends to integrate it with the new Paperwhite, I wonder what their plans might be for Shelfari. I suppose they could move all the Shelfari users to Goodreads. Doesn't make much sense to have both of them.
Edit: Just for my amusement I tried importing my Goodreads books into the Librarything. First I had to buy a membership. That's OK, $25 for lifetime, pretty cheap. They also have an easy interface to download the CSV file, but then I ran into problems because their file size limit is 2 MB and my file was over 4 MB. So I split it into 3 pieces using Excel, easy enough, but time consuming.
That worked. The import is much, much, faster than Booklikes (30 minutes for all three files compared to 7 days for Booklikes) but much less accurate. Several titles were not found and could not be imported.
At this point of the four sites I've been on GR still has the best social aspects, but that could just be that I'm more familiar with it. Time will tell.