Google is currently working on changing the algorithm to include detecting excessive Seo of websites.
One of the things they'll look at is post titles and penalize sites which stuff too many of the same keywords into the title.
Bad Example: Creating a WordPress Blog Website by Downloading WordPress Software Then Installing WordPress.
Titles like these with keywords repeated and stuffed with multiple word keywords which have the same meaning might get you penalized.
Especially if you have a lot of titles like these.
Good Example: How to install WordPress software and create a blog
If you have titles which repeat keywords or include more than one variation of a long tail (multiple word keyword) in the title, now may be a good time to make some changes and avoid a penalty.
The reason i have written this post is because my search engine traffic has been hammered the past week after changing themes which caused a problem with my heading sizes and sitemap.
It all started on Friday the 13th!
I didn't know this was the case until after i received a message back from Google stating i didn't have a manual penalty however i did go through and change some of my titles which repeated keywords and sounded a bit spammy.
Here's the response i got back from Google after asking for a reconsideration of my ranking not knowing what the problem was at the time:
April 21, 2012
Dear site owner or webmaster of http://wpsites.net/,
We received a request from a site owner to reconsider http://wpsites.net/ for compliance with Google's Webmaster Guidelines.
We reviewed your site and found no manual actions by the webspam team that might affect your site's ranking in Google. There's no need to file a reconsideration request for your site, because any ranking issues you may be experiencing are not related to a manual action taken by the webspam team.
Of course, there may be other issues with your site that affect your site's ranking. Google's computers determine the order of our search results using a series of formulas known as algorithms. We make hundreds of changes to our search algorithms each year, and we employ more than 200 different signals when ranking pages.
As our algorithms change and as the web (including your site) changes, some fluctuation in ranking can happen as we make updates to present the best results to our users.
If you've experienced a change in ranking which you suspect may be more than a simple algorithm change, there are other things you may want to investigate as possible causes, such as a major change to your site's content, content management system, or server architecture.
For example, a site may not rank well if your server stops serving pages to Googlebot, or if you've changed the URLs for a large portion of your site's pages. This article has a list of other potential reasons your site may not be doing well in search.
If you're still unable to resolve your issue, please see our Webmaster Help Forum for support.
Google Search Quality Team
How To Create Good Titles
I think the best way to create a good post title is to make it unique with the keyword you have focused the content on included in the title once and preferably towards the beginning of the title.
SEOMOz has an excellent post on Seo best practices for titles.
One of the best ways to find out if your title is unique is to Google it before you publish the post.
How to Quickly Check for Over Optimization
I found the easiest way to check titles for over optimization was to look at the sitemap of all posts and click on the ones which needed an adjustment from the front end while logged in as admin.
This is the fastest way to scan your posts and pages for duplicate keywords and other excessive Seo and over use of keywords so you can quickly make changes to your suspect titles.
I haven't changed any page titles yet but may remove repeated words from them just in case.