[InvisibleSoul]

Originally Posted by CRiXy

Anybody here do the UPDATE from 4.0.1 to 4.1?
What are the major differences?

http://en.wikipedia.org/wiki/IOS_version_history

Improved calendar colors
Bug Fixes
iPhone 4 Proximity Sensor issues
Bluetooth connectivity
iPhone 3G performance problems under iOS 4.0[48]
Nike + iPod fixes
Fixes White Balance issue with iPhone 4 under certain lighting conditions.
Fixes FaceTime error where iPhone 3G and iPhone 3GS users could enter "facetime://" URLs in Safari .
Game Center (Only available for iPod Touch 2nd, 3rd, and 4th generation, iPhone 3GS and iPhone 4)[49] no support for iPhone 3G [50]
Updated Carrier Settings (US is AT&T 8.0)[citation needed]
Security updates to Accessibility, Facetime, ImageIO and WebKit[51]
Improved AVRCP, adds support for Next and Previous[citation needed]
Enables FaceTime call connection via email contacts (e.g. for 4th gen iPod Touch users who won't have a phone number) and through favorites[52]
Check Spelling can be turned off in Settings[citation needed]
P2P App Support[citation needed]
Nike + iPod statistics submissions over Wi-Fi
Improved Battery life across the board[citation needed]
High Dynamic Range Imaging (HDR) (Only available for the iPhone 4)[49]
HD video upload over Wi-Fi (Only available for the iPhone 4 and the iPod Touch 4th Generation)[48]
iTunes adds Ping, a social music network and discovery tool[49]
TV Show rentals (Only available for iTunes US Store)[49]
Can move an existing appointment from one calendar to another
Notes syncing removed from iPhone 3G due to reported performance problems[53]
Safari 6531.22.7, Webkit 532.9[citation needed]
Restores Field Test mode[54]

The only thing I really notice on everyday use is the HDR feature for the camera... can help take nicer pictures.