"First of all, the updated operating system now runs on
the Linux kernel 2.6.27, meaning stronger security, improved
stability and a range of core applications enhancements. Android
1.5 now packs SIM Application Toolkit 1.0 and features
auto-checking and repair of SD cardfile-system. Just like the
iPhone OS 3.0, Android 1.5 comes with the SDK 1.5 that adds new
APIs which help developers create better apps. More importantly,
though, new features for end users significantly enhance the
experience, addressing most glaring omissions in the 1.0 release.
"Some of the features are simply catchup of the iPhone's, like a
new virtual keyboard or improved mobile web browser. Others are
designed to add more punch through flashier eye candy, like
animated window transitions, smooth, accelerometer-based
application rotations between portrait and landscape modes and
overall polish of user interface elements."