As I understand it, even Russia managed to give most men a new uniform on a yearly basis. But they set a lot of stock in appearance, so that may've been where the training budget got socked off too for them :P

The 'special favors' of the era probably wont be implemented in ETW. Certain units display extraordinary conduct DID get distinctions visible on the field. The Pavlovsk Grenadiers probably being the most famous example. Tsar Alexander declared that they were the only unit in the army that would get to keep wearing the old-fashioned Mitre caps. Apparently a number of these were still being worn up until WWI (complete with bullet holes from Friedland).
Other units got different honours. The big thing after the Napoleonic Wars was to give your Imperial/Life/whatever guards bearskin caps captured from the Old Guard.
Something sort of like RTW's 'First Cohort' might be kind of nice, the French would get an 'Eagle' carrier and everybody else would have flag/banner units which increased morale until they were taken, at which point they inflicted a serious morale penalty.

It'd be really interesting if there was a way to purchase different models of weapons for your units.