After installing and using Developer Preview Version: 2.3 – Milestone 1 with my current apps, I had these problems (which were not there with version 2.2.1.
On popup windows in IOS apps, the “Done” button was not there anymore.
On Android apps, the font sizes on web pages were extremely smaller than before.
Some centering of text was changed to be off-center.
On some of my Android devices, they no longer played mp3 audio files that are embedded in the program. The same build of this app did work on an Asus tablet, but not on Galaxy S and S2 phones.
Using the old way of doing email: Go to URL, did not work with iphone 4s. It just sat there instead of opening the email app.
I was hoping this Milestone 1 would allow my Android apps to read PDF files, but none of my devices would read them, either from a web page, or embedded in the app.
Thanks to the developers for all the work you are doing. Just reporting here on what I experienced.