An installation has SQL Server 2005 Standard installed on their development, test and production servers. They have to move to 2008. Is the equivalent for SQL Server 2008 Standard available? Or, if we have to change, is it better to consider something else, which would not be in the Standard family?

I personally use SQL Server 2008 R2 since a while but when I go in Help, it doesn't say exactly if this is Standard or something else. Is there anyone who can share some info on this?