I am not sure exactly when this changed but Scott501 let us know that RIM has opened up BlackBerry Beta Zone to more countries since we last noticed.
Now included are: Anguilla, Antigua and Barbuda, Aruba, Australia, Bahamas, Bangladesh, Barbados, Canada, Cayman Islands, Dominica, Grenada, Hong Kong, India, Jamaica, Malaysia, Montserrat, Netherlands Antilles, Pakistan, Philippines, Puerto Rico, Rwanda, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Singapore, South Africa, Sri Lanka, Switzerland, Taiwan, Thailand, Trinidad and Tobago, Turks and Caicos Islands, United Kingdom, United States
If you are in one of those countries you can sign up now at www.blackberry.com/beta