Can Bitcoin incorporate the scripting protocols of Ethereum without a fork? I am curious if the Bitcoin protocol can incorporate Turing complete scripting capabilities without forking the block chain. I ask this because I understand the ability to create contracts digitally is as significant an development as bitcoin.

I am trying to judge the efficacy of new altcoins like Ethereum to assess the future viability of Bitcoin.

Thanks for your comments!  Also if you are curious as to why I think contracts are so important here is my blog about why contracts are important.

Peer to Peer Government: Guarding the Guardians
http://statisticaleconomics.org/2014/01/10/peer-to-peer-government-guarding-the-guardians/
Bitcoin has a scripting engine already. At this time only a limited number of features in it are used, such as those for standard transactions. Other features are unused but can be developed upon and some, disabled (though could be reintegrated later).

Solutions are already present which build on top of Bitcoin or other such coins to provide smart contracts, m of n transactions, programmable features and more for those who want to use more advanced scripting features which bitcoin would be unable to support. 

The currently most fully featured example of this is Open Transactions (http://opentransactions.org/). It is also token-less in the sense there are no "coins" being minted in the use of the application keeping it pure.