Ignore Daysleeper's childish comments above. Regrettably you'll find that PPRuNe has been contaminated with spotters and geeks over the past few years....
So which are you??
... the term "Enhanced" when applied to TCAS might refer to the formation mode, however it is also being used currently to advertise/describe
1/The Airbus autoflight enabled TCAS as certified on the A380 and coming to other models.
2/By ICAO to describe Mode S Extended Squitter operations when linked to TCAS
3/ Civil long range TCAS displays of over 100NM for oceanic use
4/Honeywell’s CAS 67A TCAS II Enhanced/ACAS II for corporate and regional aviation
5/ Some sort of radar augmented TCAS patented in the USA.
I could go on (see I fit the geek description)
The point I'm making, perhaps a little childishly is this; without more information from the originator of the question
When do we plan to implement Enhanced Traffic Collison Avoidance System (TCAS) on our military fleet.
you don't know which technology they mean. The tendency to assume that they mean X instead of checking is, I suspect, why we waste millions if not billions on military kit that doesn't do what people actually wanted it for.