Ok, this is my take on why 4.5 has not been or won't be released.. TMo has made available the new 8220 with a new os on it and within the next month or so will be releasing the 8900 Curve II with a new os.. Why would they release a new os for a phone that will most likely be dropped from the line up fairly soon? Doesn't make sense.. The os from the other vedors works great on the tmo curve and tmo knows that the people who really want it, will get it from there.. Anyway, just my 2 cents..