From Yahoo support pages;
".htaccess (Hypertext Access)
The name .htaccess refers to the main configuration file for Apache, a popular open-source HTTP server. The .htaccess file can be used to create custom error pages and web page redirects, set up password protection, enable SSI, and more. Yahoo! does not currently allow you to upload .htaccess files to your account. For other customization options, we recommend the Custom Error Pages and password-protection features available in your Web Hosting Control Panel."
I read about a work-around for pretty permalinks once, using "index.php" in the permalink structure, but I can't say that I really know if it works or not.
Do some research before choosing a new host. I can't comment on a service I have never used, but I sure do read a lot of strong opinions relative to both Yahoo and GoDaddy.
Hers is one re: Yahoo that might make you chuckle...
This might point you toward answers for GoDaddy:
I would bet that if you searched this forum for a while using "hosting", or something similar in your keyword search, you could get a good cross-section of general opinions in both directions (pros and cons).
..and lastly, here is a great spot right off the "frontpage" to start reading about potential hosts for WordPress.
Research, research, research. I am sure if you don't find the info you want in the forums, you can come right out and ask about a specific host, and some kind soul here will let you know about their experience with them.