On the Ibuildings blog today Andy Thompson has a new post looking at some of the challenges of migrating PHP applications up from the now end-of-development-life PHP 5.2.x versions up to PHP 5.3.
According to a recent Twitter poll, we found that over 50% of developers are already working with the latest 5.3 release. An additional 35% is already in the process of migrating to 5.3. This means that the majority of developers see the importance of upgrading and are already taking action, well before PHP's announcement.
He talks about how common migrations like this are in the IT industry and how dealing with multiple releases can only cause more issues. He also mentions some of the keys to successful migrations like compatibility testing and checking of any custom code you might have implemented in your codebase.