Can i use iCloud with one apple id but app store with another; especially on iOS 6?

Question

My household has multiple devices.  I own iPhone and iPod, both on iOS 5.1.1, and iCloud (used for apps, iMessage, and backup.)
I almost never buy music, but I buy some apps.
My SO has iPhone (also on 5.1.1), and she uses my apple id for purchases (mostly kid apps.) She does not (yet) use iCloud (paranoid about it
She uses iMessage (with her own apple id.) 
Anyway, I suppose at some point she would switch to iCloud too.  It is also likely that we would move to iOS 6 once it is released (me first, likely.)
I know that Apple does not allow transferring app ownership from one account to another, as well as splitting or merging accounts.
Question: would she be able to use her own ID for iCloud (photo stream, backups) but my ID for app purchases? (I like it, let me control app expenses.)
If any of you are using IOS 6 preview, can you try this scenario (different IDs for app store, backups, and iMessage.)
Unsure if iOS 6 feature set is already public - if not, let me know 5.1.1 situation.  Thanks!

Answer 1

thank you, @randers4!
(sorry for using twitter notation - hope you would not mind.)
for other commenters (especially Tawnii) - I view Apple ID (which was before essentially Store ID) as a purse with money.  Money is shared in our family;  I don't like "get your own milk license, and mark your bottles" approach.
Currently my spouse uses her own ID for iMessage (and she does not use icloud for mail, calendar, reminders, etc - pretty much iMessage and iOS Store are only apps she uses), but we use same set of apps (mostly kid apps) on all of our devices (including iPad, which is used by our little daughter).  It does feel a little weird when purchases on one device appear on another (but this is an option which can be turned off.)  We almost never buy music or books from iTunes store.
iCloud backup for my devices uses my ID (which is same ID we use for Store.)  My spouse does not use iCloud backup.  I suppose Mountain Lion can give her incentive to use shared Photo stream, and perhaps bookmarks.
Just so you guys know, we live in a country which did not have App store permitted until recently, so it was not possible for my SO to obtain her own ID for purhasing apps, even if she wanted (my ID is U.S.-based, where I used to live before.)
I feel that Apple model works fine for individuals but does not work well for family environments - for example, I want to listen to music from both of our computers on our Apple TV, but it is not easy: I can share iTunes collection or iTunes Match music set to Apple TV, but only from one account.
And I also suppose our two-year old would not be able to use her own account, even though she is iOS user for about a year already (iPads work great for kids, we tried 50+ different apps and have our own set.)
Again, thank everybody for quick responces, this is my first time using Apple forums and I am very happy