I don't really think the game is dead, but I'd say they have to add something very basic: bugfixing, ability to name streets/buildings/put signs, sandbox mode in multiplayer etc.
Exactly. I can still play hours upon hours with CiM2, so it is definitely not dead. The last two vehicles pack are pretty cool too. However, they need to adress some of the gameplay and engine issues at least (as you mentioned), otherwise they will lose all of the remaining supporters and fan as well. In my opinion Train Fever will never be able to be as competitive as CiM2. So i definitely want some improvements. It can't be that hard, come on guys. I don't want to jump to another game...