Is there any tools available for this yet? I checked the Exchange 2007 website on Microsoft and they have tools, but the tool they have JetStress doesnt work with Exch 2007. Or am I missing the configuration for it? Is there any way to see how good/bad Exch 2007 performs on my existing hardware?

Paul, the short answer is "it's not out yet". For a slightly longer answer, see <http://www.robichaux.net/blog/2006/09/simulating_user_loads_on_exchange_2007.php>.

Thanks for the link, I will check it out today.