We've been waiting for MobileMe to go free for a while now so we're not holding our breath, but could iOS 4.2 really, finally bring a free MobileMe tier to users? MacRumors has found evidence in AppleAccounts.framework that suggests yes.
According to MacRumors:
The evidence comes in the form of a new private framework known as AppleAccounts.framework that includes a series of device-specific error messages referring to free MobileMe accounts. In particular, the error messages include alerts regarding having reached "the maximum number of free accounts" for a given device and certain devices not being "qualified for free MobileMe service".
There are other error messages restricting certain Apple IDs to be used with MobileMe Mail which suggests that MobileMe isn't going completely free but rather that certain services of MobileMe will be free. We'll presumably find out when we officially get iOS 4.2. [MacRumors]