i think by connotation these days..webmasters are more of the 'formal' thing..more on technical..has to know a lot about things..from layouting to web content etc etc..
but blogs/bloggers are more on 'everything under the sun' you just need to know what you want to post..be it personal..or even business related..or even this!PTC, PTP! with blogs a lot of people are given chances to post something on the web which they can call their own work.why?because although it has the help of websites offering free blogs, still the content is more on personal..
you can create as much blogs as you want without the technical hassles.