Hello, I just want to ask, if there will be an extension bar (or some option to add extension icons to sidebar) in a future. Thanks.
There will absolutely be extension visibility on toolbar. There will absolutely be configurable toolbars and the ability, at least to a large degree, to add and remove and move toolbar buttons. So the answer to your question, though the developers might not have in mind specifically "extension toolbar" right now, would seem to be inevitably, yes.
A user defined bar would be great - for extensions as well as for search fields like in Opera and maybe for custom actions (I often created "Open in IE", "Open in FF"… to check web sites created by me in different browsers)