This is a little work around that I've been using for a while.

I need to check my home email alongside my corporate email on my WM device.

In addition,   I need to check my personal calendar contacts etc. off of my home exchange server., when I'm out an about.

So I'm still using the long forgotten about Outlook Mobile Access (OMA).        Give it a try if you use Outlook Web access just change your normal outlook web access from  http://YOURURL/exchange   to http://YOURURL/oma

If you do this on your Windows Mobile device you should get a screen that looks like this -

So there you go,  how to check multiple exchange accounts on one mobile device.