Take for instance the fact that MSFT only offers crippled POP3 access to Hotmail/Live.com, thus making those nearly worthless on the iPhone. Thankfully the fine folks at FluentFactory make just the thing to make Hotmail/Live.com mail on the iPhone nearly what it should be (for those of us with a many, many year history with our Hotmail accounts).
But that said, looking at what Google has to offer for synching to the iPhone, I can't help myself from laughing!
The following paragraph copied from that page is the key:
Important! Google Sync uses the Microsoft© Exchange ActiveSync© protocol. When setting up a new Exchange ActiveSync account on your iPhone, all existing Contacts and Calendar events will be removed from your phone. Please make sure to back up any important data before you set up Google Sync.Pretty sweet when Google licenses ActiveSync from MSFT for connecting GMail for use on the iPhone, while MSFT refuses to offer the same functionality for Hotmail/LiveMail users, even the paid ones like me! WTF MSFT?!?!?!