I did a comparison of favourite distributions and the result shows a clear trend towards Ubuntu, while the interest in all other distributions declines. However please also note that this might also indicate that a lot of people use Ubuntu and have problems with Ubuntu and are looking for help. Personally I believe its a combination of both. First there is a high interest. On the other hand there are excellent resources for Ubuntu and people know that Google is of great help for Ubuntu problems, while I wasn't able to get so much help from Google for SuSE problems in the past.

Google Trends comparison for various distributions.
A big surprise was the regional results. Italy is the clear leader in searches for Ubuntu.