The April CTP is newer than SQL Express beta 2. The SQL 2005 team has decided to move to a series of CTP releases until RTM, with a new release every six to eight weeks.
People who would like to "Go Live" with SQL Server 2005 can contact Microsoft about the Technology Adoption Program.
Regards,
--Oren
Yes, the April CTP is meant for use with the rest of the Beta2 stuff. You can have them running without issues on a single machine.
Regards,
Vikram
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