I’m all for changing “weblog” but not to “channel”. I use channel to describe a collection of content (single/multiple weblogs, forums, gallery).
e.g. on my current site I have multiple channels: music, movies, tv, and books. There is a blog post “weblog”, an image “weblog”, and a forum post “weblog” – not to be confused with the similar modules. I have a category group called channels which contains the above list of available channels, and is available to to each “weblog”.
Each channel has a page with the latest content from all weblogs belonging to the channel (category).