Here are some diagrams on the VtES Storyline "Eden's Legacy" that is currently still ongoing. The diagram to the right shows all clans with more than one win. The Guruhi are in the lead, but Brujah and Ventrue are not trailing far behind.
An interesting fact to note is that all four Laibon already have won at least one storyline tournament. I am not 100% sure, but I think that's a first.
On the left you can see the distribution of winning clan's sect. This may not be 100% accurate, since technically you could play a "Harbingers of Skulls" deck with mostly Laibon vampires for example. Most interesting is that the Sabbat is narrowly in the lead, although three non-Sabbat clans are in the lead. Speaking of scatteredness of this sect ...
[Statistics from the Eden's Legacy Storyline standings webpage as of December 11th, 2009]