Today, the actual version is 2.3.4.
The version in portage seems old (2.0.1). It is due to a lack of maintainer or to a difficulty to upgrade?
Thanks for the report. It may be that jmeter in tree is old simply because java team didn't get feedback that it was being used, perhaps your report will be the motivation to update it...
Another bumb version request was made before. But it was miss misnamed :/
*** This bug has been marked as a duplicate of bug 158498 ***