I am thinking to create a smart contract where miners are not only incetivized by gas price but where basically the miner can get other assets like erc20 tokens if he/she mine my transaction in the next block. This would look like the tx fees in Bitcoin where the unassigned money is in the hands of the miners. I'd like to have a formal address argument in my contract which can be assigned at mining time with the actual address of the miner. I've never seen anything along these lines but I wonder if it is possible today or will be anytime soon.
For this to work clients would have to update to account for your specific token and the rewards around it. If anything it might be good for a standard to be implemented around this where miners could query a contract to see the reward for including transactions to it. There's no problem with it being possible, since you can access the block.coinbase to get the miner's address, but it's kind of useless without adoption in clients.