Just a heads up regarding iOS 7; use caution if you NEED your phone.

Aside from the myriad things that can go wrong with a major OS upgrade like this, what has happened the last few times Apple released a major upgrade is that many people were left without a functional phone for a few hours as your phone needs to reauthorize itself with Apple after an upgrade, and those authorization servers get overloaded even if those serving the software upgrade itself do not.

If I recall correctly, when iOS 6 was released, many peoples' phones did not authorize for an hour or two.

I also recall that for many the upgrade process itself took multiple hours to complete, and then there were quite a few "teething" issues that needed to be worked out (one of the biggest was that Wi-Fi wouldn't work anymore, with people being asked to log into a website at Apple for which they had no login or password.)

Likewise I recall the iTunes Match servers were swamped, so many were left with a blank music list for a day or two.

Therefore, if you know you're going to need your phone within say three to four hours of when you plan to do the upgrade, you may want to wait until later this week when the traffic to Apple's servers slows down a bit.