Ahhh..the whole "I love you" thing...I have many thoughts on this. I think there are so many ways and times to say this phrase and it means many different things depending on the situation. To me, the "I luv you" sent via text is kinda like a casual thing, not the "real" thing. It's as if you (or he for this example) are just trying it out to see how it feels. I wouldn't get caught up in the text message-when he says, "I love you" in person, it will mean something else and it will be MORE meaningful when it happens face to face. But, it is nice even to see or hear it... You know what I mean?
I have been married 13 years and while it was great the first time my now husband said, "I love you", and it meant so much, it was still more about that fun and dizzying "I love being in love" thing. Now when we say "I love you" it is a really different and obviously deeper and more meaningful. So, I guess what I'm saying is to appreciate the fact that he is testing the water with you via the text message and you should look forward to very good things to come when it happens face to face (and know that it gets deeper and more meaningful as time goes by and you share your lives together)!
Every guy who has ever said "I love you" to me has always struggled. I'm assuming this is a guy thing and not a me thing. At least I hope.
One decided to say it another language (dumb), another waited until I got mad at him for teasing me (lame), and yet another said it all nervously and awkwardly and waaaay too early. First of all, I think saying "I love you" for the first time is slightly overrated. I mean, it's great to know and it's wonderful to hear but I guarantee the first time it's said is not the first time it's felt and usually both parties know before the words get uttered. To me, it's just a stepping stone to be able to vocalize the feelings that both people already know are there. (In most cases, that is.) I like the point where you can say the words without feeling awkward or nervous. It's an important sentiment to express and it still makes me happy to hear my BF say it (even though he's said it for what seems like ages and ages).
As for a text message, it seems kind of immature but like I said, every boy has his own problems with saying those words, imo. Since you're going down there in a few days, why not wait until then to ask him about it? Maybe after a nice dinner with a bottle of wine in tow, or something like that. I'd just wait and feel out how everything is going because knowing that saying something like that can bring out "the serious ugly" (hee! I've been waiting to say that!) in people maybe makes it easier to understand the awkwardness of the situation.