This proposal aims to register DOT as a foreign asset on Zeitgeist and to allow it in pools. One of the reasons behind this is to tackle liquidity issues, as Tom stated:

I think having DOT based markets on Zeitgeist is one of the best things we can do to help with liquidity issues. There is 7 billion dollars worth of DOT that can now easily be transferred to our chain, nothing else really comes close. For comparison, circulating DOT is worth around 10000x more than circulating ZTG

Since DOT has 10 fractional decimal places just like ZTG, it can be used right away in markets without further adjustments in the runtime code. This is one of the reasons why registering DOT before any stablecoin is recommended.

DOT integration was tested on all technical levels on Battery Station. Every involved party gave green lights to move forward on the mainnet. You can see and interact with the prediction market that uses (fake) DOT as a base asset at https://test.staging.zeitgeist.pm/markets/625 (request fake DOT from Tom_#2021 or sea212#9780).

When receiving DOT from Polkadot on Zeitgeist, fees are charged in DOT as it is not certain that the receiving account has ZTG to pay the execution. The amount of DOT charged is specified as 143120520 (0.0143120520) times the fees in ZTG. This value was derived by dividing the 25 week moving average of the ZTG price by the 25 week moving average of the DOT price.