I am not sure that "unconditional" love exists in the sense that you're putting it forth. Daystar and I have discussed this. I think we come close. But we all have "expectations". We all have fear of loss. You can love someone and choose not to be with them because either you or they have evolved into a "different" entity than the one you fell in love with in the first place (like he might evolve into a couch sitting, beer drinking unemployed schlub LOL!). It does not decrease the love you feel for the person they are Now.
It is difficult to articulate. There is a difference between unconditional love; that connection you feel to another being at the soul level: That never changes, whether you are together or not. and good old committed marriage. No matter where your/their personal evolution takes you. You simply love them. You cannot help it--it flows from you freely once the well spring has been tapped. Does that require togetherness? Does it require "rules"? It is so beyond that which is perceived "good/evil". It is a state of being. You can choose to be with that person and that makes it all the more powerful but the love does not require it-it just is.
Now, most relationships (and up to this point in my life it has been all I've ever believed in) are business relationships with the added fluff of "romance". BTW, romantic love is a rather new invention to the human populace (and wildly popular here in the west) to further our pro-creative activities and perpetuate the human race with rules/boundaries that have served us well. The family unit is the most basic form of human government and it usually mirrors and ergo furthers the society it "lives" in. So, committment and behavior modification and rules and making people stick to it are good in those situations and you can have some semblence of romantic love on top of that but make no mistake, it is ultimately a business. Not bad, imo. I have cared deeply for and been a fantastic wife (one good thing I got from the witnesses was training on being a good wife) to a man that I did not necessarily love but we made good partners. We were friends/partners. And actually still run a business together; that of raising our son to maturity and an actual business. He and I both knew when we decided to get married (when I got pregnant) that it would very much be a business relationship. But there was romance and there was committment (still is in the raising of our son). Problem was, he wanted more. I wanted more ultimately. He developed emotional intimacies (that I did not care about) as did I, with other people. We talked about staying together (though we had lived in separate bedrooms for sometime) for the business end of it all--we have always been good partners. But decided not to. I actually think we would have stuck it out to our deaths do us parts except for the flaw of him treating my daughter like a piece of crap.
So, there is a difference between unconditional love (which is very rare in a non parental relationship) and good old committed marriages. One just is, the other serves a very utilitarian but not altogether unpleasant purpose.
You may find this book of interest: Getting the Love You Want http://www.amazon.com/Getting-Love-You-Want-Couples/dp/0805068953
I found some use as I slept in my bedroom and he slept in his and we were trying to keep things together. It helped me delve into all my unconscious drives and heal many of those. I only diverged when Hendrix speaks of finding what you're looking for in the other. I personally believe that the individual holds it within and the key is finding it within. But a good read nonetheless.
I hope you find what you need within and without....
Love and Light,
~Brigid