Sort of. That is, traditionally XAML has been used primarily for Silverlight & WPF applications, but it's actually just a declarative language used for laying out (usually) Silverlight & WPF controls.
It's sort of a combo HTML&CSS. So your statement in that vein would be like "Isn't HTML&CSS just another name for Gecko and/or WebKit?"
That said, even though it looks like XAML may be used for new WinRT-based apps in the Windows Metro stuff, I'd be surprised if it survives the deaths of Silverlight & WPF.
It's sort of a combo HTML&CSS. So your statement in that vein would be like "Isn't HTML&CSS just another name for Gecko and/or WebKit?"
That said, even though it looks like XAML may be used for new WinRT-based apps in the Windows Metro stuff, I'd be surprised if it survives the deaths of Silverlight & WPF.