Are dividends paid by an ETF that invests in REITs taxed at the "qualified" dividend rate (typically, 15% vs. the ordinary income tax rate)?
(If I recall correctly, REITs are not subject to double taxation, so I don't think the favorable dividend tax treatment applies to them, but I may be wrong.)
They aren't qualified, because the REIT is a special kind of company, and not double-taxed like a regular corporation (as you mention). The income from the real estate holdings gets passed straight through, similar to how a mutual fund passes any interest or capital gains it earns straight through to shareholders.
To avoid the double tax the REIT has to agree to distribute 90% of its income to shareholders, rather than keeping it inside the company. That ensures that while the taxation is only "single," it doesn't get deferred indefinitely into the future. For a normal corporation, paying a dividend is optional and can be put off forever if desired.
In most cases REITs don't pay dividends, they pay distributions which are treated differently.
Here's a REIT Tax-Equivalent Distribution Calculator: http://www.dinkytown.net/java/REITTaxEquivYield.html
Probably not to any appreciable extent, if Vanguard's REIT fund is any indication:
https://personal.vanguard.com/us/insights/taxcenter/qdi/yearend-qualified-dividend-income-2010
