Why change to an iCloud email address?

I suspect everyone received the email from Apple indicating an iCloud email address had been reserved for them.

All new iCloud Mail accounts now come with an @icloud.com email address. As an existing user, we'd like to offer you this new address as well. We have reserved xxx.xxxx@icloud.com for you, and you can now use this address with your iOS devices and computers by following these simple instructions.

If you prefer, you can continue to use your current email address just as you always have.

No matter which address you use, you'll continue to receive all your mail, whether it's sent to your @me.com, @mac.com, or @icloud.com address.

But the instructions didn't indicate any reason to change. Are there good reasons to change from my DOTme address?