I'll throw in my two cents. First, I echo everything Andrew has said. The statement "Several search engines will be unable to index your site" is a little odd - a 301 is the proper method for redirecting in a way that is acceptable to a bot without penalty. Your site is redirecting from www to non-www. If that is not what you want, you need to change that. And, if in fact, that is a recent change, then yes your rankings could definitely be affected in Google. They can and may see a page with or without as two different pages, splitting your page rank.
Make sure the settings are what you want and consistent in the WP
General Settings area as well as in your Google Webmaster Tools. You may need to reverify the site there.
Regarding content, I'm not sure if I understand properly but it sounds like originally your 'blog' page was your home page but is now the 'news' page. If that is so, then again that will affect your rankings because the content HAS changed as far as the way Google sees your site. What was on the homepage is now no longer there (again, if I understood you properly - I may not have). This is not fatal, but as Andrew says, any time you make such a change it is common to see your rankings get shaken up for a week or two.
Make sure you have everything set all www or non-www as you prefer, keep an eye on things and adjust content, links, etc. gradually as necessary. Keep adding valuable, relevant content to the site overall and try to rank for a variety of terms on various pages.
Keep at it and good luck!