Over the last few days I’ve seen that google is starting to decrease the space where they display sitelinks. Previously sitelinks were displayed for some search phrases, for the first SERP result. They could have up to 4 extra lines, and 8 inner links to other pages on the top result. As you can imagine that having sitelinks for a top keyword would really increase your relative CTR, because of having more options to inner pages and the fact that you have more real esate on google.
Here is an example of the older view, for the keyword “Recruit Ireland”

But now on certain phrases (perhaps more general queries) these site links are compressed on one line.
Site Links Jobs
In this climate the keyword “jobs” is highly sought after, but it’s also possible that it is just too general of a keyword to merit expanded sitelinks.

upon searching for “jobs.ie” you will get the full expanded version of their sitelinks.
Site Link Cars
And here is a further example for a highlight competitive keywords “cars”, on google.ie.

It will be interesting to see how traffic is effected by this recent change by google. It could mean that there will be a higher CTR through to your homepage, as sitelinks are not always shown up so prevalent. For those of you in positions other than first, I would expect that by making sure your keyword description that little bit more appealing you will be able to benefit from this change.
Sitelink Tip
Did you know that you can control your website’s sitelinks on the google webmaster console ? Here you can remove links that you don’t want to appear in your sitelinks.
4.17.2009
Google has posted about this topic at http://googlewebmastercentral.blogspot.com/2009/04/one-line-sitelinks.html it’s great that they come out and talk about these things.