Jeff wrote an interesting article about this on the Stack Overflow blog, comparing it to the main Stack Overflow site where you have
[php] all living together, separated by tags and not by sites. If you would have asked people about this beforehand, they would most likely favor different sites per language. However, the "mixed bag" approach seems to work there, so why not here?
I also do think that we should increase promotion of the site, and I do not necessarily agree with those who say everything is OK, and "we'll see in a few weeks". We are already half way through the beta period, and I think we need to work on increasing the number of questions asked and answered per day. Merging with related proposals could increase the overall weight of the site, and give us more chance of survival and growing beyond that.
Update: With the Popularity Contest app, I created a graph with the number of questions in the last 30 days. WordPress answers is the fat brown line. (The current on-line version of the graph does not have the fat line and some data errors.) Of course, this only shows questions, not answers - and we still score low when compared on daily traffic.