Boy Genius Report are claiming that a source of theirs has told them that iOS 4.3 will be available from Apple via iTunes today at 10AM PT. Tuesday is the normal day that Apple pushes out their iOS updates, and the Gold Master went to iOS devs last week. Normally a sign that the next release is imminent.
BGR have also been told that the much anticipated personal hotspot feature will be feature limited according to network providers stipulations. If your network provider is kind then they can request that you be able to connect to up to 5 devices. Otherwise it will be three by default.
Let us know how the update goes for you in the comments below…