The HR-bashing that went in the comments of this Slashdot post ("Social Networking Sites Getting Risky for Recruiting") makes me think that HR in general is not doing a good job of marketing itself. I've had good experiences and mediocre ones with HR in the various companies for which I've worked. Understand that in the mediocre situations I've experienced, HR's staff has set itself up as one of the "gatekeeper" roles that I despise so much. That's symptomatic of a culture problem across the entire organization, so we won't go there.
But the substance of my questioning of HR's role in hiring comes from my head-scratching at the notion that a company gains any efficiencies by delegating even so much as the resume pile vetting to a centralized person or group. IMO, it becomes more of a liability as the company grows. To my mind, there's no reason why any team lead worth the title shouldn't be trained in (at a minimum) technical interviewing.
The bottom line is that team leads and first line managers know what skills they're looking for and have strong sense of the culture of their teams. Moreover, their understanding of what the resume actually says is considerably deeper than the buzzword bingo that so often is played when a non-technical professional is weeding the resume stack.
Mind you, an HR professional should attend every single interview to insure that nothing illegal happens, and (if necessary) to keep the interview from bogging down into minutia. If the professional's also been trained in reading non-verbal communication, by all means consider their opinion. But the hire vs. no-hire call must be made by the people who will be most closely affected. Anything less is a paint-by-numbers cop-out.