As I mentioned in my last Office for the iPhone post the folks at DataViz and Quickoffice keep going at it back and forth with improvements to their Office products. It looks like DataViz took the lead from Quickoffice with their latest release I just read about at The iPhone Blog site. DataViz renamed their Documents To Go with Exchange Attachments product to Documents To Go Premium and added some functionality that I know many have been waiting for, including PowerPoint and Gmail support. It hasn't appeared yet on my iPhone as an updated version, but it is a free update if you already purchased the program. It didn't show up as an update on my iPhone, but I took the leap of faith and chose to buy it and then learned it was a free update because I already owned it. Documents To Go Premium is available for $14.99 from iTunes (iTunes link).
I imagine the support for PowerPoint will appeal to the business user who travels with an iPhone and wants to edit a presentation before arriving at their venue, but doubt this is something the masses of iPhone owners care too much about. The PowerPoint support actually looks quite good with support for bullets and text in outline mode, speaker notes, and slide management. DataViz is cranking out the updates for the iPhone and IMHO this is the current winner in the iPhone Office war.
The support for Gmail attachments could be quite huge and make the program very attractive. I thought there would be a separate Gmail setting, but found out directly from DataViz that they are supporting Gmail through the Exchange ActiveSync protocol so you can use EITHER Gmail or Exchange, but not both. I will stick with Exchange on my iPhone since I receive many more Office attachments through Exchange than Gmail. You can always send out Office documents through any email client you have on your iPhone too.