Yes, the use of CLR requires that you're on SQL 2005... Given that we're mid-way through the year 2008 and SQL 2008 is now available, I don't think it's unreanosable that anyone starting new development would be using SQL 2005.

Also, it's not unlimied, the command string you pass to xp_cmdshell can be either an nvarchar(4000) or a varchar(8000). I was wrong about the ascii requirement.