I just came across a very good post by Paul Robichaux on Windows IT Pro under Exchange and Outlook section.
Paul discussed the demand versus availability of Exchange Server 2010 32 bit management tools very well in his post.
Bottom line of the post talks about zero expectations to see a 32 bit management console for Exchange Server 2010. Only Microsoft can tell how difficult is it for them to write a 32 management console code.
Personally, I would do a favor for a whole new x64 architecture offering a more memory addressing capabilities and performance. Yes, it does include cost to upgrade the hardware and software both but sticking back to legacy versions of hardware and software holds you back from upgrading your skills yourself.
Companies do have budgets for their IT infrastructures and may not tend to spend more money towards upgrade. But an upgrade may also help the heldesk and support teams to perform their jobs easily and much faster than they used to do. Normally, an Exchange support engineer needs to have a well equipped computer with troubleshooting tools where he/she may also need to work with some tools which demand more memory and high performance systems.
Also, if you are favoring to have a 32 bit Exchange 2010 application for your test labs then you probably need to understand that testing a performance of application on a 32 bit platform will be drastically different than having it tested on fully functional 64bit platform.
Read more about this story at Exchange 2010: No 32-Bit for You
Considering all above aspects and few more highlighted by Paul in his article probably many people may think of changing their thoughts on demanding a 32 bit management tools or the whole software for test labs.