First of all, 1080i cannot be 60Hz, because 1080i is 1920x1080 @ 30Hz, making it Interlaced. 1080p is 1920x1080 @ 60Hz, and it refreshes twice as much as 1080i, therefore delivering a faster picture that doesn't stutter compared to 1080i. That's why 720p was better for gaming over 1080i because it isn't interlaced, but now we have 1080p. I guess you know nothing about the resolutions and refresh rates of 1080i and 1080p.
And some people like me need HDMI since my VGA is already taken up by my HTPC. Some other HDTV's as well, like Sony's XBR line, won't accept 1080p through Component or VGA, but only HDMI, so others will not be able to view 1080p, only 1080i. And in the future, you will not be able to view HD DVD's in Analog such as Component. Yeah you can view 1080p through component, but only a few HDTV's can handle 1080p through component, and only games can be viewed through component 1080p, but not HD-DVDs.
And for the future, only HDMI (1.3) will be able to view 1440p and higher!