At the company analyst event in Chicago, Motorola showed off their i880 and i885 cross-platform phones that work on both Sprint's CDMA and Nextel's iDEN network. You can interpolate from that that they'll both support the push-to-talk sound everyone loves to hear.
These two phones are the first "fashion" phones for Nextel, but if you ask us, being shaped like a Transformer doesn't exactly exude "fashionable" on any network except for Nextel's. Both phones have a two-megapixel camera, music buttons and a press-to-open button on the hinge.
The i880 and i885 should be available by the end of '06.