So far, general opinions from the replies are
(1) Bitcoin and Ethereum will not be affected because other projects including those by IBM and Microsoft targets different fields.
(2) Some of other projects are centralised and controlled by financial institutions and government bodies, so Bitcoin will be a winner due to its decentralisation characteristics.
Personally, I believe Bitcoin has more potential as system (i.e., the largest blockchain) than as currency. It is because that using two currencies at the same time in one country sounds unrealistic to me (e.g., a Wall Mart labels the price of pencil with two different currencies and the exchange rate of the two currencies varies over time) and that the money supply should be varied depending on a domestic economic condition (to manage inflation or deflation, for example).
With respect to Bitcoin as system, there are several interesting side-chain projects (e.g., rootstock) which will increase the transaction of Bitcoin when they are successful and adopted by public. Increasing in demand will definitely lead to a higher price. As others replied, IBM and Microsoft would target different fields. However, the eventual goal of the projects would be overlapped with Bitcoin as system and might disturb the increase of Bitcoin and Ether price.
With respect (2), if IBM, Linux or Microsoft provide more efficient and better platform for designing blockchain app or services, I think people would not mind building apps and programs using those platforms, because many people have credit with the aforementioned companies in terms of security and reliability. For this reason, it would not be that Bitcoin will be a winner because of its decentralised characteristic.
More comments and replies are welcome