Yes, I've already taken a look at preferred stocks. They are indeed an interesting class, but it seems to be quite overbought. It's precisely because the dividends are good that many investors have flocked to them, which renders them expensive. And you propably know the risks of going for something that's really popular to the point of a small bubble being formed.
The opinions I read said that this was a bad time to enter preferred stocks, as they're overpriced. I should wait until a correction happens.
However, they might be a good way to fruther diversify a portfolio. They don't have very high correlation with neither bonds nor normal stocks. I even asked in a forum about their opinion on including preferred stocks but I never got any reply.
By the way my current ETF allocation is:
5.49% XEMB.MI - db-Trackers Emerging Markents Eurobonds
14.40% IAU - iShares COMEX Gold Trust
5.10% DBC - Powershares DB Commodity Index Tracking Fund
12.96% TLT - Barclays 20+ Year Treasury Bond Fund
4.97% ITE - SPDR Barclays Capital Intermediate Term Treasury
5.35% VSS - Vanguard Small-Cap ex-US
9.18% VNQ - Vanguard REIT ETF
11.32% VBR – Vanguard Small-Cap Value ETF
11.09% VGK - Vanguard Europe
13.01% VPL - Vanguard Pacific
7.33% VWO - Vanguard MSCI Emerging Markets ETF
Unfortunately I suffered with the treasuries tumble and my portofolio is slightly negative for the time begin. I learned what it means 'sell in May and go away'.
I've been wondering about some of the choices I made, namely buying VGK and VPL instead of a single ETF for developed markets. The two indexes are so correlated that it's almost meaningless to have two separate ETFs. Same goes for USA small cap and ex-USA small cap. There's not much diversifying at work in there.
Having too many ETFs can be costly in terms of transaction costs, particularly when you work with an European broker. But if I eliminate VSS and VPL, I should have room for two other ETFs. The classes I had in mind were, like I said, preferred stocks, and possibly TIPS, treasury inflation-protected securities. I read in ETFtrends that short term TIPS might be more useful than regular TIPS due to the very likely rise in interest rates of US debt.
If only I could solve the problem of double taxation of dividends when working through my broker....