Your reply caught my eye. I would love to capture leads and send RSS emails through Mailchimp, but integrate subscriber data with Marketo to indicate the lead's subscription status as well as create new lead records in marketo when someone new signs up for the blog.
Any more direction you can provide on that?
In the past I've used Perkuto and their product was a great help. It still lacks some features for advanced customization, but the hours of work saved make up for that.
You can take a look at the WordPress Integration from Hoosh Marketing. The solution allows you to send automate blog updates and digests, and also build newsletters by simply tagging the posts you want to add.