Windows Live Writer Beta is available for download, which I'm testing out, so far I really like it...especially the preview since I've had issues w/ font sizes in the past.
More info: Windows Live™ Writer is a free, downloadable program that will help you include rich content in your blog posts and know exactly what your blog will look like before you publish it to the Web.
What it gives you
• WYSIWYG editing: Edit using the style of your blog, including fonts, colors, line spacing, margins, etc.
• Rich content: The ability to insert and customize rich content like photos, maps and more
• Offline editing: Support for offline editing to compose posts even when you're not connected to the Internet
• Blog preview: Rich HTML and source-code previewing of your blog post before you upload it
• Smart image publishing : Smart image publishing directly to your blog automatically links your thumbnails to larger images with more detail
• Compatibility: Support for publishing to Windows Live Spaces, as well as Blogger, LiveJournal, TypePad, WordPress, and many other servicesChange the size of your graphics, and add borders and other effects