Selected answers from the Dumb SEO Questions Facebook & G+ community.
Brent Wildman: They're not really shutting it down. Just integrating it into the keyword planner. ;
The reason they're doing that is to make it easier to create PPC campaigns and Adgroups, which ultimately leads to more spending and more money for Google. They're not too concerned about how SEO's and Marketers are using it.
Justin Y: From what Ive read its just not going to be available to the public but still available to those that have an Adwords acc or gmail.
Amresh Kumar: +Justin Y ;you are correct . if you have adwords a/c so can access .
Bhupendra Rathore: Thanks everybody Its cleared my doubt. Your inputs on this will be greatly appreciated. thanks again !
Andrei Gherghel: It may be a google strategy to attract more adwords customers.
Any body knows the reason `Why Google going to shutdown its Keyword tool ?` 
