On the flip side, my boyfriend, my husband, and I all have tendencies toward shyness and often use email to discuss things that we have difficulty talking about in person.
My husband and I have been together for 11 years. Our friends tell us that they look to us as an example of a couple that really works, and that we give them hope for their own relationships because we are happy, close and loving.
We have also, in the past, had a problem communicating our needs to each other, so my husband started composing emails to me to express his feelings. This aided our communication greatly, and we are now able to discuss things in a manner that we can both understand and relate to. If things get bumpy again, we'll probably go back to emails again.
My boyfriend and I discuss our relationship via email often. He says that, while he is often uncomfortable discussing his feelings in person, he feels that we could talk about just about anything in our letters. He is a bit shy and gets embarrassed by praise, so I express many things to him via email that would fluster him in person. Over the course of our 3 months of intimacy, he has become much more open with his feelings and his ability to accept and express affection verbally. I know that our text communications greatly sped up this process.
So, I would have to disagree that greater comfort communicating via text is a sign of potential problems... at least not anymore than just about anything can be seen that way. It is a normal part of my relationships, and has paved the way to greater intimacy.