Update! This post will tell you how to use WordPress and Joomla together for better SEO results. If you are looking for some ideas on how to choose between the two, you could read the Page How to choose between WordPress and Joomla!
If you look at these Opensource Content management systems, then people use them for Blogging and Building websites.
Joomla
Now Joomla with al its extensions is great for building a good solid website with all the features you want. And you can bring it to high rankings in the search eninges as well, if you start with the proper technical improvements.
Templates in Joomla make it easy to get a good layout for the site, and you can find lots of good free Joomla templates. For a good business website I suggest you look for a good commercial template based on a Table less design with external css files.
WordPress
For Blogging you cannot beat WordPress, especially if you do the right setup, making the permalinks work right the .htaccess file and set the options to /%postname%/. Creating posts and giving it the special keyword tags is really easy.
Templates for WordPress are also very easy to obtain and to implement. Besides that…Google loves WordPress Blogs
My advice?
Use them both!!
Setup your main site in Joomla! and start working on the content, create good quality content.
In a sub directory, or a subdomain, install WordPress and start blogging, using the keywords you also use for your website.
WordPress with its create SEF functions and categories will bring you traffic, this traffic reflects to your main domain.
And with the content on your main website, you work to keep your visitors captured and make them come back.
Yes, I know there is a great Component to integrate WordPress in Joomla from j-prosolution.com (Site is no longer available, but a great Premium replacement that can be Found on corePHP) and I use it also on my website www.pathos-seo.com And if that is not enough, they even use it for the news via blogs on http://www.joomla.org/ !!
Still I like the separate installation better, because there are more features I can use for Search Engine Marketing and Viral marketing.
In my short experience with combining them that the combination of Joomla and WordPress are a killer combination for getting High Search Engine Ranking!