The creative tab labeled "Transportation" has a different icon than in Minecraft 1.4.7 because it shows a non-powered rail rather than a powered one. This could be intentional, but personally I thought it was cooler the other way.
Environment
Windows 7
Java 1.7.0_04
No mods
faithful32x32 texturepack
Duplicate of MC-7112, please use the search function to see if your bug has already been submitted. Currently over 54% of tickets are being closed as duplicate.