I've given a lot of thought to the TL;DR approach to content digestion. It works extremely well, in a vacuum, or on the site it was made popular, reddit. Their, the original poster writes the TL;DR, which is why it works so well. If you write a large post, then immediately after summarize the post into 1-2 sentences, it becomes a very efficient message that still expresses exactly what you wanted to get across. TL;DR is the future, almost to a sad degree. A lot of time it digs deeper than just wanting to filter out the articles you have no interest in reading. But this becomes the only form of digesting news. You begin consuming a lot of news, stories, articles, but you're no longer actually informed on any of the topics, you just end up with a vague idea of what is going on around you. That's far beside the point though.
This is a actually a very nice effort.
The issues I have with growth and actual value, is with how the summaries are generated. Automatic generation is fast and inaccurate, manually curated is slow and very accurate. In a world where people no longer have the time to read newspapers, their not only looking for quick news on the run, they want current news. Something that happened today, everything that happened today. But quick, not the full story, "i'll read that later." Meeting in the middle between fast and slow approaches does not work here. You're too slow, and the headlines in my RSS feed and twitter have already informed me of the news, too fast and your summary becomes a failed attempt to make twitter and RSS better quality. I have no idea how your TL;DR are currently generated. But I would think you'd have an aggregation and be doing some manual curation. To me for this to really work, you'd have to have a large group of people that read the article generating the TL;DR, constantly iterating, until you end up with an extremely efficient 2 sentence summary. Or there needs to be a project that integrates TL;DR on large scale, the publishers, news papers of the world, blogs..They submit these directly.
I think there's still a lot of value in what you're doing. I just don't think it will take off as it is now. Away from the name/marketing/novelty/social aspect not really being there. Twitter, RSS feeds, and sites like http://skimfeed.com/ end up providing me with far more day to day value. If you took this and spoon-fed me the TL;DR via my phone, i'd consider being a repeat visitor a little bit more. But you'd then be competing with a whole 'nother slice of the pie.