As posted in AOU...
Posted by Sezmra, the official word has come down concerning the small client that players could download and install if they did not have need of expansion content. Once the 18.7 patch hits live, the small client will no longer be supported.
Now would be a good time to get ahead of the curve and download the large client if you are in the group of those that only installed the small client. Since the date for the patch has not been announced, you don't want to be caught off guard and not able to play.
You can get the large client Here!
The END of the "SMALL CLIENT" (but not of froobs): UPDATE!
The END of the "SMALL CLIENT" (but not of froobs): UPDATE!
Doolittle / Snakebite just provided this important info