@Mad7Scientist
Good job gathering all of this information. This is easier to read and more condensed then the coverage provided by most of the bitcoin news blogs.
All users of bitcoin will have to change their software or continue using the classic wallet, but the classic wallet will be stalled and it will take ages to confirm a transaction because most of the mining power left and because it takes a long time for difficulty to adjust back down to 10 minute blocks.
The old client will still work but if the network moves with the hard fork no one will accept transactions from the old folk. You will have to update your client in order to send or receive transaction that the rest of the network accepts.