Apple distributed an e-mail recently to MobileMe subscribers that detailed some improved features, but the biggest news from that e-mail was the fact that push is back.
Push was part of the initially tragic launch of MobileMe in 2008--a launch so poorly implemented that the word "push" was removed from descriptions of MobileMe until synchronization between computers and mobile devices (i.e. iPhone and iPod Touch) would perform at an acceptable level.
Now that push is in business again, syncing with Macs or PCs is faster. Any updates that you make to contacts or calendars on your Mac in iCal or Addressbook, or on your PC using Microsoft Outlook are automatically and rather quickly pushed to the cloud. Conversely, any updates made to MobileMe data at me.com, or on an iPhone or iPod Touch is pushed back your Mac or PC. Finally, all your contacts and calendars will update across your devices much faster than previously.
In order for all of this to work properly, you must be using Mac OS X Leopard 10.5.6 or the MobileMe PC Control Panel 1.3. The iPhone or iPod Touch must have firmware 2.2 or later.
Read Apple's letter to MobileMe subscribers below and note the additional information about file-sharing using iDisk, which was previously announced a few weeks ago.
"Dear MobileMe member:
Over the past few months, we have been working hard to make MobileMe the best service it can be. Here is a summary of the improvements and performance enhancements that have recently been completed.
Easy file sharing. iDisk now makes it even easier to share files that are too big to email. Simply select a file in the iDisk web app and click the Share File button to generate an email with a download link. You can also optionally add password protection and set an expiration date for the link. For more details, view this tutorial.
Faster syncing with Mac and PC. Changes you make to contacts and calendars on your Mac (Address Book and iCal) or PC (Microsoft Outlook) are now automatically pushed up to the cloud every time you make an update. Likewise, changes you make on me.com, iPhone, or iPod touch are automatically pushed to your Mac or PC. As a result, your contacts and calendars update faster across all your devices. To take advantage of faster syncing, be sure you're running Mac OS X Leopard 10.5.6 (Mac) or MobileMe Control Panel 1.3 (Windows).
Improved notifications and sync on iPhone. Reliability of new email notifications and syncing of contacts and calendar with MobileMe have both been improved. To get the best MobileMe experience on your iPhone or iPod touch, you should be running iPhone Software 2.2 or later.
Better web app performance. We have also improved the overall performance of the web apps at me.com including faster start time in Calendar and searching in Contacts. For more details, see this support article."