I hear you.
But I can't see why you have so much accounts for only you two...
I joined iTunes in 2001. So did my wife.
That's 2 IDs, both using old, retired email addresses.
Then I joined DotMac a few years later (MobileMe) and I started using that email address for everything (and it's automatically an Apple ID for lots of interaction w/ Apple).
That's 3.
Not to mention Apple Discussions (which my wife thankfully has as the same as her iTunes) but I have a separate one (an old work email address).
So, really, that's 4 Apple IDs for one household. But only 3 that are attached to purchases.
She bought iTunes stuff before we got married, as did I. Then, after we moved in together, and got iPhones, etc, she was buying apps, etc, w/ her ID. I was buying stuff w/ my ID on iTunes but once the AppStore came out, it used my MobileMe ID.
THEN we got the iPad, and it has NO idea which ID to use. I can switch between them but that's not the point.
And there are THOUSANDS out there with in the exact, same predicament.