Today saw the monthly NPD data release, which provides sales details for gaming software and hardware in the U.S. The results for May didn't feature any Nintendo titles in the software top ten, possibly due to a fairly heavy-hitting month of releases on other platforms.
There was some positive news for Nintendo, as 3DS was the only system to enjoy a year-on-year increase over its sales in May 2011, with a 17% improvement. Eurogamer.net estimate that this puts the handheld's sales for May at around 113,000 units. While still not at the level of the country's leading seller, Xbox 360, this increase is positive as last May, of course, wasn't long after the launch itself.
With a growing games library and more on the way, this is a sign that the system is achieving a decent level of consistency, and will no doubt hope to improve as the year progresses.