To make a short story even shorter, this offers just a few added features, forces you to go 64 bit and does not solve the BIG problems with Exchange. Exchange Server remains a massive black hole in which your staff communicate secrets that you are liable for and can not see or even find.
In my opinion these Exchanges are some of the last Enterprise versions to see wide distribution. Email servers by logic will migrate to the Cloud over the next 10 years. Companies would be wise not to invest to heavily in Exchange Server implementation or rely too heavily on revenue for thier company.