Whirlwind,
There certainly seem to be others, from a quick websearch I did. I believe that Theta Nu Xi is [inter]national and you are asking about other [inter]nationals (upcoming or established) so I'll list those.
- Delta Xi Phi Multicultural Sorority. Link
- Sigma Iota Sigma Multicultural Sorority. Link
- Zeta Sigma Chi Multicultural Sorority. Link
- Lambda Tau Omega Multicultural Sorority. Link
- Mu Sigma Upsilon Multicultural Sorority. Link
- Omega Phi Chi Multicultural Sorority. Link
- Lamba Psi Delta Multicultural Sorority. Link
- Chi Delta Beta Multicultural Fraternity. Link
- Psi Sigma Phi Multicultural Fraternity. Link- working?
- Phi Sigma Chi Multicultural Fraternity. Presently just in NY area. Link
- Gamma Omega Delta Multicultural Fraternity. Link
There are of course, I believe, numerous local multiculturals out there. A search in any main seach engine on "multicultural sorority" or "multicultural fraternity" should find more.
I hope that helps a little.
-- Richard.