I'm not sure I understand your question...MaxEnt is already in use in some NLP applications. For more on this see: http://www.alta.asn.au/events/altss2004/course_notes/ALTSS-Curran-Maxent.pdf
Many Thanks for the link. It contains important information.
I would like to know when might you choose to use a MaxEnt model rather than other models? Which argument could be used to substantiate, prove and attest the use of MaxEnt model?
Well, depends on what you want to do. For my thesis, I am testing the application of a MaxEnt model on a learner corpus for detection of a certain kind of error. I suggest you read http://www.ets.org/Media/Research/pdf/han_chodorow_leacock_LREC04.pdf
The argument, in my view, is that MaxEnt is shielding good results with a reasonable small source of information (for this problem, not so useful for other problems).
For a general explanation of MaxEnt, read http://repository.upenn.edu/cgi/viewcontent.cgi?article=1083&context=ircs_reports
MaxEnt has also been applied to an analysis of the Voynich Manuscript.