It is the new and improved Cubby. It even has a new name, My NCBI.

You must register to use My NCBI.
Good news to those of you who have Cubby accounts, your login and passwords work for My NCBI and all of your stored searches and preferences have moved to My NCBI as well.

In addition ot a new look and feel here are a few difference sbetween Cubby and My NCBI.

My NCBI allows you to have your searches automatically emailed to you monthly, weekly, or daily (your choice). Emails are sent in the format of your choice, HTML or Plain Text.
You can check the date of you last update. Simply go to the My Saved Searches page and in the Last Updated column you will see when last update was generated, either automatically or by you.

My NCBI also includes a new Filters feature which groups search results by areas of interest. You can have up to five active filters using My NCBI. You can also add an icon to the filters with links to resources provided by outside organizations. (This function replaces the LinkOut preferences in Cubby.)

For more information go to the NLM Technical Bulletin or Help Section for My NCBI.