I just un-boxed a new Palm Treo phone Monday so that I could activate it and synchronize it with our Exchange Server for a doctor. It was running Windows Mobile 2005. For those keeping track, Windows Mobile is up to version 6.1. This was a Verizon serviced phone but our other local cellular provider, Embarq, will also sell you a brand new phone with a three year old operating system.
Microsoft discontinued version 5.0 for several reasons. The primary reason was to create a new product with a few new features so that they could raise the cost of licensing. If you have used Windows Mobile 5.0, you all ready know the other reasons that they did away with it. It's slow as molasses and it's so loaded with bugs that you will find yourself soft-booting your phone at least once or twice a day.
So why do you have a brand new phone with a three year old operating system? Because cell phone companies and Microsoft both behave like greedy little children. In the end, it's you that is losing for having to carry around a failed product in your pocket.
If you are a victim, do yourself a favor and head over to http://www.PPCgeeks.com. You will find that many have resorted to downloading bootlegged and unsupported operating systems for their phones so that they can make simple phone calls.