[Ansovald]

Question whats in this update?

went to backup my 9900 on my pc and the update popped up..and its a slow update.

[PiotrJot]

It is OS 9900 7.1.0.794
You can read all about it here: Latest 9900 Official OS 7.1.0.794 from China Unicom
And just BTW: there is more recent version online. Just have a look on the sticky thread on the top.

[elite1]

Yes .825 is most recent available. Here's the thread, as mentioned above:
Latest 9900 Official OS 7.1.0.825 from Vodafone DE

You have more control over process if you download the OS yourself and install locally on your PC before loading to your device. Here's where to find all OS's:
BlackBerry - Desktop & Device Software Download Sites for BlackBerry users - Canada

Here are installation instructions posted in same thread (but works for any version 9900 OS):
OS UPGRADE GUIDE