You have several things all jumbled up. Try to straighten them out so you can analyze them. One, dilution is not a good thing, but the preferred offering is not dilutive if it produces the same or greater income per share as the common. Two, it is more debt and potentially more leverage if the amount raised by the preferred is leveraged to the same extent as the common. Three, since the preferred is not dilutive, and more leverage is not dilutive, your conclusion that there will be less dividend is incorrect. Just take a deep breath and try to think things through rather than just giving a knee jerk reaction that is not correct.
No one has the data to know this for sure. How can you expect people to say what they do not have the data to draw such conclusions on? The people who are stating a value are just making it up and are probably the low IQ posters on the board who say things they know nothing about because that is what they are hoping is true and I would recommend that you pay no attention to them because they are misleading people with their made up information.
All anyone can do is speculate on what the future might bring based on what is likely to happen with interest rates and hedging. Exact numbers can only come from AGNC themselves and are given in quarterly reports. Right now I suspect that the book value posted on yahoo is out of date