This is a great news for Arduino community because recently Arduino 1.0 was announced. As promised it came with lots of changes and improvements that many will love and some will have because old arduino code might not always work out of box.
But we love changes and new stuff, aren’t we? Most noticeable remakes that pops out are: different sketch file extensions. They were replaced from .pde to .ino to represent more relation to arduino and draw a line between Processing. New breeze to toolbar icons. You will find a check-mark icon for verifying and arrow for uploading sketch. No more guessing on compiling and uploading time – a progress bar was introduced. Probably most was done under hood lots of changes to core and libraries. Major influence was made to Serial class, Ethernet library where DHCP and DNS support were added. SD library was improved – now with ability to work with multiple open files. And of course lots of more stuff you’ll find in release notes.