Intellisense for SQL, how hard is that? Well judging for how long we have been asking for it the answer is “very”. Also talking to the product team it is actually much harder than for C# VB etc. because of the nature of SQL.
Anyway intellisense appeared in CTP5 of SQL Server 2008 and at that stage it had a few niggles in it which have now been fixed. One of those niggles was that it didn’t check which version of SQL Server it was running against, so you could use intellisense against SQL Server 2000/5 for example. However the downside was that it was directing you to write SQL Server 2008 compatible T-SQL, which would work most but not all of the time on the older versions.
Rather than try and make intellisense work for the older versions, in RC0 and RTM it does now test for the version and is disabled if the target isn’t SQL Server 2008. This isn’t going to please everyone as some people thought this was going to be implemented for all versions, but it was never intended to support legacy versions, given how hard it was to develop.