rsstvc> If it is from the phone manufacturer, then yes. But Android doesn't allow dual-sim by default. So to support it, the manufacturers had to implement the functionality themselves. Since Android is opensource, they could modify the codes and add this feature. I don't know if the source codes are available so knowledgeable people can modify them. Chinese manufacturers are known for not obeying GPL licence (which forces them to release the modified sources).
Because the modification to add dual-sim support is quite complicated, I don't think they will release Android 2.3 update anytime soon.