Consolidating all of my servers using hyper-v

Dear Experts,

Three or Four years ago, we deployed Windows Essential Business Server 2008 comprising of a management server (DC), and Exchange 2007 server (also a DC) and an ISA server.  Around 6 months later, Microsoft sent us a letter informing us that they were no longer developing EBS and that we could take advantage of a 'Make it right kit' which allowed you to covert to standard servers and still use the EBS licenses to cover.

We now want to virtualise all servers onto 1 beefed-up box and this is a good time to 'drop' the EBS 2008 config and migrate off to separate virtual servers. The servers specs are currently:

Management server
HP Proliant G6, 24 GB RAM, SCSI disks for OS, HP DAS unit with SATA disks for Data.

Exchange server
HP Proliant G6, 24 GB RAM, SCSI disks for OS, HP DAS unit with SATA disks for exchange stores.

ISA server
HP Proliant G6, 16 GB RAM, SCSI disks for OS and Logs.

SQL server
HP Proliant G7, 24 GB RAM, SCSI disks for OS and Data.


The general plan is to:
1. apply the Microsoft purpose-built utility to remove all EBS features (see http://support.microsoft.com/?kbid=983141)
2. create a temporary hyper-V host server and migrate off exchange 2007 to a new VM.  This will free up a server and DAS unit which will become the new hyper-v server
3. populate the hyper-v server and DAS unit with lots of disks
4. build the new hyper-v server and move the exchange VM (created in step 2) to it
5. migrate the other servers off to new VMs hosted on the hyper-v server
6. as each physical server becomes free, relocate a processor and RAM in to the hyper-v server

During this process, I want to drop ISA and SCE altogether in favour of a hardware firewall.

MS have instructions for migrating the servers off to standard products, transferring the specific roles and features which I will follow.

Q1.  Does this plan sound feasible?
Q2. Any gotchas to watch out for?
Q3.  Will the hyper-v server with 2 physical quad-core processor and 72GB of RAM be powerful enough to run all of the proposed VMs?
Q4. I intend to use one of the spare servers and a fully populated DAS unit for backups using Acronis with hyper-v agents. Anyone know if this is suitable?

Thanks in advance.