Yes, they simplified the interface. Especially with widescreen monitors it pays to have as little useless bars on top. On my 4:3 screen I immediately enabled it.
Right click in the address bar and check "menu bar" to see it. That, by the way, already existed in IE8. But maybe it was on by default while in IE9 it's off by default. Small change, easily corrected.
Kees

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