Cool, I was thinking "Cremation of Sam McGee" and there you go and refer to it. I didn't realize it was widely known. (It's treasured around here.)
I think I made pacts... I'm "blood sisters" with at least one person. I don't remember many of them though which is not good. I'm not still in contact with many people. A few, sporadically. The last time I saw one of my best friends from childhood didn't really go well and I feel badly about it. I had just moved to Chicago and had a newborn (~2 months old) and was generally uncivilized -- at that point I was talking to my husband and the (nonverbal) baby on a daily basis, and that was about it. Hadn't yet really met anyone in the area. She was in town and stopped by... she got lost and was a good two hours late, which threw things off re: the baby (E.G. was out of town? at work? not in the picture), and the baby was fussy, and I had a terrible time dealing with the baby while also trying to understand this old friend, and it was kind of a mess. (Plus I was in classic harried-new-mom mode -- yay, my socks match, there's my sartorial accomplishment for the day -- while she was in high-gloss professional mode.) Nothing terrible happened or anything, we were happy to see each other, she was nice and understanding (and I was understanding re: her being late), it just was generally unsatisfying.
We haven't connected since then, would like to try to find her again (she's not on Facebook, or at least isn't visible).
Condolences on the loss of your friend, farmerman.
(You know about the concept of happiness "set points," right?)
One further thought as I re-read your post, I have had intense friendships as an adult, too. I tend to be a serial BF'er, which is to say I've pretty much always had a close friend with shortish gaps, just that close friend changes, mostly because one or the other of us move. (I stay friends with everyone who was ever a close friend as an adult, starting at 18 or so, but when you don't see each other often it's hard to maintain that level of closeness.) About to Skype with my most recent close friend, who moved a few months ago. Skype helps, but...