A WebmasterWorld thread says that Google has increased the title tag limit from 66 characters to 70 characters. By that I mean, some are reporting Google is showing the blue clickable link with a maximum character limit of up to 70 characters, which is up from 66.

Some are even saying that the title tag is wrapping to the second line. Personally, I do not see that but I am seeing some titles that are up to 69 characters and I am sure if I dig around enough I can find some that are 70 characters long.

Tedster, the WebmasterWorld administrator, validated this observation by saying:

Some are saying this dates back to March but I am not sure if anyone noticed back then.

Forum discussion at WebmasterWorld.