When you run BibTeX, the .bbl file (which is loaded by your \bibliography command) contains the commands for setting the thebibliography environment. Assuming you have an appropriate bibliography style (or one close enough that your references can easily be modified to fit the specifications of the journal), you can just take the output from BibTeX and paste ...
You can change option the authorconversion= to one of the following: normal, normalshort, normalinverted, invertedshort, short
(See Table 6.3 in the publications manual)
The options for et al. are controlled with: etallimit= and etaldisplay=
In these situations you can use a dirty trick to fool ConTeXt into thinking that something has been typeset. Instead of typesetting the bibliography normally, you typeset it in a box and store the result without ever actually using the box. This is facilitated by the \start...\stopnointerference environment.