Ask HN: Where to Blog?

I've been working on my startup for the last few months and I've got to the point where I've got a load of things to blog about relating to work I've been doing on the startup (Mainly ruby/rails stuff).

I already have a blog, which has ~1k rss subscribers and gets about 500 uniques a day.

My question is: Should I use my current blog to write about there things and channel traffic to the startup from there, or should I start a blog for the startup and post stuff there.

Note: My app hasn't launched yet, although it should be ready to roll in a couple of months.