[TxMt] State of autocompletion in Textmate

I'm interested how it would be possible to create an autocompletion plugin/bundle for Textmate and ruby. I realize there is ESC, but I would like to open a menu with say CTRL-SPACE and then see all the possible completions based on the entered characters. Then when I continue typing in the editor, the menu adjusts it's contents to show only the matching entries. The user can navigate the menu and choose an entry to be inserted in the editor. Like auto completion in eclipse, Visual Studio or XCode.

I found this article: http://macromates.com/blog/archives/2005/06/09/code-sense/ and wonder what the actual state of code sense is in Textmate. Is it possible to create a Plugin/Bundle that controls an auto completion menu?

Ruben