Microsoft has announced, in the Office Sustained Engineering blog, that they will be moving away from the current weekly schedule for the release of Office hotfixes. Instead, every 2 months a cumulative update will be released. The first such update will appear in August, 2008.
The blog announcing the development does not go deeply into the reasons for the change, other than to say that "[t]he primary goal is to deliver high quality fixes in a predictable timeframe." It's also possible that, being more cumulative than individual hotfixes, the new updates will keep configurations more consist ant, and therefore testing easier. On the other hand, the blog says that, even though the updates will come in a package with multiple updates, "...[c]ustomers accepting hotfixes will not be required to install anything more than they install today in order to take advantage of a cumulative update." So that sounds like you can pick and choose hotfixes to install from the package.
Customers will also still be able to demand "Critical on-demand (COD) hotfixes." These are for emergencies only, and presumably they are rare.
The new approach will not change the schedule or contents of public updates, including service packs and security updates.

Microsoft To Deliver Office Hotfixes in Scheduled Cumulative Updates
