Code Outlining has been part of Visual Studio since VS.NET 2002. If you're not familiar with it, code outlining is a feature that allows you to expand\collapse regions of code in the editor to make it easier to focus on specific sections of code.
SQL Server Management Studio is based on the Visual Studio editor but it wasn't until SSMS 2008 that IntelliSense, which includes code outlining, was added. One of the drawbacks, however, is that IntelliSense only works when connected to a 2008 server…sort of. As it turns out, code outlining works if you open a multi-server query regardless of what versions the servers you're connecting to are running.
Given this fact, I personally don't think that code outlining should be tied to SQL 2008 connections and I've opened a Connect feedback request to let Microsoft know. If you agree with me please take a minute to visit and vote for Connect ID 480714.
I should also point out that if you want code outlining NOW you're in luck – check out the SSMS Tools Pack from Mladen Prajdic at http://www.ssmstoolspack.com, which includes not only code outlining but a slew of other useful features that will improve the SSMS user experience.