Does burnt transmission fluid means I need a new transmission?

Yesterday I was driving my 2000 Ford Taurus SES. As i was driving it started to decelerate, but didn't turn off. (This has never happen before. My check engine light wasn't even on.) So i pull over check under thing a belt popped that wasn't the case. So i get back in and try to continue to drive, it won't go over 20.
So I got it towed to a repair shop. They told me the transmission fluids are burnt really and needed to be flushed and the filter kit needs to be replaced but if they flush it its a 50/50 chance it can fix my car or continue to ruin the transmission.

Sounds llke a 50/50 chance it will need to be rebuilt/replaced. Putting the money in a flush fill and fliter after the trans has gotten so hot to burn the oil is probably putting good money after bad - but a good way to quickly (and fairly inexpensively) diagnose the problem.
Personally if the flush and fill works I would dump that car so fast it would make your head spin. Trade it in immediately.

If it was the trans that was slipping and the cause of you not being able to move then it would be a waste of money to flush the fluid. Put the money towards a rebuilt trans.

Find another shop!

No way in heck a flush will repair a broken transmission. In actuality, a flush can ruin a working transmission!

Not necessary means you need a new transmission but it could be the fluid and filter needs to be changed, no flushing, just change the fluid and filter! The smell also could be the cat. Converter clogged up!

Needs rebuilt. If you smell burnt fluid that means either a band or frictions are gone. Fluid and filter change is just that change no repair. Find local shop at ATRA.COM for more help

If you get lucky and it works after the new filter is on be aware that the friction materials likely
have been overheated and the transmission may not last long. Then it is Craigslist time.