Your title says L--LL.com & your post says L-LL.com, which are you asking about??? Personally, I can't see L-LL.com being "the next big thing". I'd rather own L-L-L.com over an L-LL.com anyday. I would suggest not just trying to chase fads & study what makes a domain valuable then you'll be able to make your own decisions to what type of names are worth buying.
two dashes continuously are a turn off. L-L-L is better that L--LL this holds true for all .com, net etc
Again it depends on the name, some may make sense, for example the ones with i and e prefix but random ones won't have much value in the future imo.