You will need it in the future since Creative lab have the largest market share so it will be supported in the future.
Sound card usually last pretty long Live have been around for about 4 years before Audigy come out.
The Aureal Vortex2 SQ2500 is a great soundcard, the Superquad version is available at compgeeks.com for only $14! A3D should stick around for at least another year on most new games, and A3D 2.0 is far better than EAX for positional audio. They also have a hardware equalizer built in (with a software interface), a handy feature that can enrich your experience with no loss of performance (ulike software solutions).