That is exactly the opposite of what happens in Crossfire, the two GPU's are utilised, but the VRAM pool is not combined. A 260x crossfire still only has 2GB VRAM.
However, 260x falls completely outside of the category of 'cards worth SLI or Crossfiring', I would definitely recommend getting a single 270x, or perhaps even better single GPU solution. Crossfire profiles has been lacking lately from AMD and there are some crossfire issues that is not worth the headaches with a pair of low powered cards.
for AMD these days, the cards I generally would consider crossfiring are 290 or 290x, any lower isn't really worth it.