I am currently using blockchain info
I just want to ask, is there any possibility that blockchain will cease its operation? What will happen to my btc with them?
There's a possibility it will cease operations, there's a possibility it gets hacked.
Relying on others to keep your money safe is not a great idea imho.
You should keep some change wherever you think it's better for you - blockchain, or even better multibit - and the big bucks in a very safe place, like offline-generated paper wallets, small-medium amounts on each wallet.