Ok I just spent an hour writing here and it deleted my post so I'm going to try to paraphrase as much as I can.
I've been in a relationship for nearly 10 years with a beautiful woman and a year ago I finally popped the question. We have what I imagine is about as close to a perfect relationship as you can get. We're very close, rarely have problems, and when we do we talk through them, and are both very quick to say we're sorry. We laugh like you wouldn't believe and overall are just very in love.
A little over 10 years ago I was in a very quick but extremely powerful relationship w/my best friend at the time. We also had close to a perfect relationship until... bam, graduation happened. She was going away, I was staying behind, to make things easier she broke it off. It was very hard for me, and I think it was hard for her too. To say abrubt might be an understatement. After she moved we have seen each other a total of 2 times, neither of them being in over 6 years. We have had a few nice but short conversations, the majority of them online, over the years, and few bursts of text messages every now and then. She's been through the standard gaunlet of crappy guys since then and sadly I still stand as the only guy that never cheated on her. Through the few conversations we've had I would say that we were close but we definitely still got along extremely well. At one point she jokingly said that we would be married by now if she hadn't broken it off. Without a doubt true. Then last year after I got engaged she coincidentally got a job out of the country... and hasn't been back since. I don't know if it has anything to do with me, but the timing was very strange to say the least.
Now for the "problem" if it is one. Last night I had one of those dreams that are so real, it might as well have been real. I was at some kind of get together that I knew my ex was at, and she knew I'd be there. Just like in real life we hadn't seen each other in over 6 years so we were very excited to see each other. We talked for a while (dream talk so I don't know what the conversation was or anything) then after we were done talking we stood up, hugged, and I walked away. End of dream. I woke up feeling like I had just won the lottery. I guess what concerns me most is that I haven't felt the pure ecstacy I felt this morning... since I was actually in a relationship with her. The happiness quickly turned into roller coaster of emotions all day making me feel like I've done something wrong. Or that I should NOT be this happy about DREAMING that I got to hang out w/my ex. This has never happened before. Over the years I played off any "feelings" as just fond memories. Is it possible that I'm still in love w/someone after this long? Is it just pre-wedding jitters? I'm sure my fiancée would be thrilled to hear about it.

With a wedding coming up I think that you mind is just re-visiting the things that have happened in the past. Sort of like a mental processing and ticking the boxes off.

There is nothing wrong with dreaming about an ex and feeling good about it. You met, hugged and THEN YOU WALKED AWAY. It's a dream of completion. You've let her go!

Don't worry if it has introduced a seed of doubt. Remember, it's a dream and you're actually with someone that you love a lot.

As an aside, I occasionally still dream about my ex, and we're usually having sex. I don't interpret this as cheating or a wish to go back to him. It's just my mind processing what I had and filing it away.

I agree with Gemini, there is nothing wrong with dreaming about an ex as long as it is left there.

Do I think you can still be in love with someone after 10 years?
Yes

And not know it?
No

Do I think you are still in love with your ex?
No

I think that you are just mentally processing old relationships and walking away from them. Look at what happened, you talked, hugged and walked away... if this happened in real life I would call it a nice reunion and a healthy goodbye. My advice would be to take it as such and continue in a life that you are admittedly very happy in.

I dream about my exes all the time at some time or another, but the feelings those dreams produces in you fades when you get busy with reality.

Nothing wrong with feelings of love for an ex, as long as you don't act on those feelings, or get carried away by them.

You don't have to share those dreams, or the feelings from them with your intended.