What made you pick this representation in particular?
I'm kind of curious what different kinds of algorithms you might have looked at.
Summarizing only blogs posts seems a bit limiting to me. (Btw, I'm not trying to be negative, congrats on your success! texteaser looks great!)
I implemented a custom version (mainly changed the scoring scheme to include TF/IDF of words for initialized scoring) of TextRank and loved it.
The main thing I liked about it was how general it was. Words are nodes and sentences are vertices. Then you basically use pagerank to rank the sentences according the graph representation.