I think it is very important that they update their current extensions to use MySQLi ... but I also hope the updates will continue to work with the deprecated MySQL extension so users can choose the way they want to work and continue to maintain older sites. When a feature is deprecated it is very important to provide the alternative early and I thank WA for jumping on this for us.
If you rely on a web host of any sort (ie: do not use a self-managed server) then you need to be even more concerned. It may not happen for a couple years - but sooner than later scripts will stop failing completely if you are not using MySQLi or PDO.
