Hey folks according BGR (Boy Genius Reports) sources Apple will be releasing iOS4.3b3 today some time. The website states that:

One of our Apple sources has just let us know that the company’s iOS 4.3 rampage isn’t slowing down. We have been told there will be yet another beta build posted for developers, wearing the build number 8F5166b, at some point today.

It will be only available to developers. As this will be the third beta in the 3rd week. So we can see the full iOS4.3 a public release before the Verizon’s iPhone4 Launch event or soon after that. We will update you as soon as we hear any thing new on it or come to know about the release of it.

Source [BGR]