Last October, Google released a new interface and along with that came blue triangle arrows used with the keyboard to navigate up and down the search results with your up and down arrow keys.
Reports are coming from the Google Web Search Help forums that Google may be removing this feature.
Some users began noticing the arrows have gone missing, in which Matt from Google replied:
We've removed the keyboard navigation arrow from the default search experience. But don't fear! This feature is still available by pressing "Tab" after performing a search. This change is part of the clean and simple redesign of our search results page.
Honestly, I still see the arrows and I think Google may have changed their mind and put the arrows back after these few complaints. I am not a 100% sure, but I am pretty sure Google may be keeping them and not dropping them, despite what Matt (not Cutts) said from Google.
Forum discussion at Google Web Search Help.