It's astonishing to me how people think Apple can change Microsoft's products, and refuse to accept even Microsoft's own admission that it is Office that does not support CardDAV and CalDAV.
Do you not understand? Can't you read Microsoft's own support article, or are you just blind to Microsoft's faults?
Apple does not make Microsoft Office. Apple did not make MobileMe compatible with Office - Microsoft did by adding support for Apple's proprietary SyncServices protocol. If Microsoft wants Office to be iCloud compatible, then it is Microsoft who has to add CardDAV and CalDAV support. No-one else can do it.
Apple have finally done away with their own proprietary sync protocols used in MobileMe and have started using established, cross-platform, industry-standard, and open sync protocols. Doing so means iCloud customers can potentially use any CardDAV and CalDAV compatible sync client on any platform.
Microsoft Office is also not compatible with any other online calendar system which uses CalDAV, such as Google or Yahoo calendars.
Microsoft have chosen only to support their own, proprietary Exchange sync system in Office. However, Apple has added Exchange support to Apple's Mail and iCal applications. So, in fact, Apple's applications support more sync protocols than Microsoft's. Why aren't you complaining to Microsoft?
Only supporting your own proprietary sync protocol is what's arrogant. Supporting both industry standard, cross-platform protocols plus competitors proprietary sync protocols is the exact opposite.