Microsoft has released the RTM version of Load Generator (32 & 64 bit) and Jetstress. Both tools have been in beta for a while.
Load Generator is a simulation tool used to measure the impact of MAPI, OWA, ActiveSync, IMAP, POP and SMTP clients on Exchange servers. The tool allows you to test how a server running Exchange 2010/2007 responds to e-mail loads. To simulate the delivery of these messaging requests, you run LoadGen tests on client computers. These tests send multiple messaging requests to the Exchange server, thereby causing a mail load. LoadGen is a useful tool for administrators who are sizing servers and validating a deployment plan.
Download the 32bit version here
Download the 64bit version here
This version is intended for Exchange 2010 and 2007 Servers only.
Jetstress is used to verify the disk performance by simulating Exchange disk Input/Output (I/O) load. The tool simulates the Exchange database and log file loads produced by a specific number of users. You use Performance Monitor, Event Viewer and ESEUTIL in conjunction with Jetstress to verify that your disk subsystem meets or exceeds the performance criteria you establish.
Download Jetstress 2010 here