I have had several of my students to contact me over the last few weeks because they’ve thought some of the links they have built to their websites have been lost.
Typically in SEO, one of the ways we can tell which links we built are indexed by the search engines is by is by checking the links to the domains in Yahoo. Although this hasn’t been entirely accurate as we know there are many more links than what we can see in Yahoo, the technology change that has occurred recently with the Yahoo/Bing search alliance is that the links showing in Yahoo are dramatically less than what they were even a few weeks ago.
No one has lost their links so don’t worry that your links have disappeared. At this point it however, it will be much more difficult to see what links your competitors have and that will make SEO a bit more difficult until this is sorted out. There are other tools such as Majestic SEO that have a copy of the Internet (I know that sounds weird, but they have been indexing pages for some years now) and you will get a much more accurate report of links using this service.
Of course, comparing many different websites to see how many links and where their links come from is more difficult this way.
My advice would be to continue building links as you have been and monitoring your search positions. I have seen no change in your website rankings as a result of this.