Winston Churchill wrote:
Yes, you can use your existing ID for both iTunes and iCloud, while your spouse uses it for iTunes and has her own ID for iCloud.
If I decide later to initialize a third (3rd) Apple ID for my own iCloud materials, how does that effect my iMessage (iOS) and Messages (OS X) history / experience? I guess that would have other implications for any data stored in iCloud on what we've been calling Apple ID #1, wouldn't it? Beyond just the messaging components?