HTC and Sprint have released a ROM update to enable Rev. A speeds on the Mogul. You can download it from http://www.america.htc.com/support/mogul/software-downloads.html 

The key benefit is faster upload speeds. Over 10 times faster. 145Kbps to 1.8Mbps. This can be especially useful when uploading video, streaming information from the device or simply sending a large file to via email.  Rev. A also provides roughly 50% faster downlink speeds (2.5 Mbps to 3.1 Mpbs)