well, let's pretend for a moment that I just recently started with the whole Java thing
I solved it by
v.set(something(p));
instead of v = something(p);
outside of the method.
Sometimes being too deep within game logic lets you forget the most basic stuff.
post script:
Does the getXAxis() method create a new vector internally, and if yes, do you plan to add a parameterized version like getTranslation(SimpleVector) ? Any other ways to elimiate as much object creation as possible besides from not using calcAdd etc. ?