Crush is finally out of other relationship...what to do?

Two summers ago, I worked with this guy very closely for 9 hours/day. I realized within days of meeting him that he was somebody that I would miss after the summer ended, but I didn't realize that I had romantic feelings for him a while - they crept in slowly, and one day it just hit me. He was funny, sharp, kind, cute, easy to talk to...and he genuinely seemed to enjoy being around me as well. We clicked immediately, and we made a great team, even working in a fairly high pressure situation.
However, he was also in what appeared to be a very serious 3-year relationship with another co-worker that he had known since high school, though he didn't mention it for quite some time, and I found out through other people. I decided that I wasn't going to let that stop me from being his friend, and we just grew to be closer and closer. One day one of he and his girlfriend's mutual friends mentioned to him that she thought that he was "paying too much attention to me." There was just something about the whole situation that made it clear that he and I couldn't really socialize outside of work or work-related social events. This made me sad, but I didn't let it bother me too much - I was just so glad that he was in my life.

I left for college, and assumed that we wouldn't really talk. But my first week there he called just to make sure that I was doing well and making friends. This pattern continued for that year - we wouldn't talk for awhile, then he would make the contact. In some of our conversations he hinted at the fact that he felt trapped in his relationship, but I didn't really take it to mean much. We worked together the next summer, but not in such a close situation. It hurt me that we couldn't be as close as I wanted, so I pulled back. He sensed it, and pulled away as well.

Even though I consider him to be the best guy I've ever met, I got over him because I thought that there was no way that he was going to break up with his girlfriend of 4 years. However, in February he randomly called me after not talking for 6 months to just talk about life, catch up, and...to tell me that things weren't going well with his girlfriend (who he was living with). Long story short - they are now broken up. I was the first, and only person he called to talk about it with (not his roommates, or his parents, or any other friends), and we talked for an hour and a half. He really laid it all out - at first it really shocked me, because I was really seeing him at his worst. However, he's a lot better now that things have died down.
We have been talking since then - he calls me just to say "Hi" and we just end up talking about life. I have never had a real boyfriend, but I am a fun, intelligent, driven person with a lot to offer. I am just very independent and careful in my choices, though I feel that I am finally really ready to have a relationship.

My question is: If a guy just got out of a 4.5 year relationship (his first real relationship), how long should he/I wait before contemplating anything? Does it seem like he is actually interested? I am at school across the country right now, but he has said that when I come back he would love to see me. Would you call somebody that you liked to comfort you when you were going through hard relationship trouble? Or would that person just be a friend?

 

hmmm
how long ago did they break up?
i see absolutely no harm in tellin him youve been interested in him a long time.. you can state it in a weay thats not too risky, not like omg ive wanted you forever now we can be together.. but more asd a freind building up a hurt freinds esteem by admitting a secret crush and see how he reacts

if your the only 1 he talked to then your the 1 whos opinion mattered the most..the 1 he trusted most..all good signs
bur admitting too much is opening yourself to rejection..too little and ya maybe passing up your only chance

so if i were you id make a statement like " i know we've been freinds the past 4 years through this whole relationship and im not sayin this to ever jeapordize our freindship, but..i always thought you were such a great person..a real catch, and well there was a time i had a secret lil crush on ya"\
and if his reactions favorable ya can kinda add "and i sorta still do'
\

g'luck