It seems some ISPs are blocking access to WordPress right now. Much of India, for example, and at least some of the Midwestern US, cannot properly open WordPress.com blogs. THe fault in their case lies with the ISP, who has apparently put WP.com on some kind of censor list. They will have to contact the ISP and ask them to Whitelist WordPress.com. At least in the US, that should be successful at resolving the problem.
I’m in Canada and see your blog fine and see no reason it would be filtered out by corporate or school filters.