I had this same problem, so I started building something, here:
http://github.com/rileydutton/Exchange-Web-Services-for-PHP
It doesn't do much yet (basically just lets you get a list of email messages from the server, and send email), but it would be good enough to use as a basic starting point for doing some more complicated things.
I have abstracted out a good bit of the complexity that you would have to slog through using php-ews. If you are looking to do some raw, powerful commands with the server, I would use php-ews...this is for folks who just happen to be working with an Exchange server and want an easy way to do some basic tasks.
Oh, and it is MIT licensed.
Hope that someone finds it useful!