Bagholder
Bagholder is a person who bought a house during the quick run-up in price, and who is now stuck "holding the bag" so to speak.

Bubble Top Price
Bubble Top Price is the median home sale price of houses in 2006 (at the very top of the bubble).
Please note that the Bubble Top Price is often lower than the perception of 2006 homeowners/potential sellers. For example a potential 2006 seller of a $300,000 house (based on comparable sales in 2006) may have an incorrect perception that his house is worth $450,000 (based on asking prices he may have seen for example). So if his house price declines to $150,000 by 2015, the decline will be of 50% ($300,000 -> $150,000). However, the seller will probably think that the decline is from his $450,000 "dream price", resulting in "incorrect" price decline of 66% ($450,000 -> $150,000)

Haircut
Haircut means Price Loss. "He took a 40% haircut" means "he lost 40%" or "the price declined 40%".

Fake bottom
Fake bottom is a short-term price stabilization (or minor short-term price increase) within the large picture of long-term price declines. Over the next few years we'll have lots of fake "housing bottoms", that will be followed by further/greater price declines.

Price to Income Ratio
Price to Income Ration is the relationship between the median home sale price and the median family income. The historical standard Price to Income Ratio is between 2.0 and 3.0. 2.0 ratio means that if the median family income in the area is say $40,000/year, then the median home price will be $80,000. 3.0 ratio means that if the median family income in the area is the same $40,000/year, then the median home price will be $120,000.

Sell now or be priced in forever
"Sell now or be priced in forever" is a play on "buy now or be priced out forever" that so-called "Real Estate professionals" used to say during the bubble years. "Sell now or be priced in forever" is the very real and unpleasant dilemma that bagholders face. Their first option to sell means to take a loss, or a haircut. Their second option to hold on to the house means to keep making indefinite house payments that are greater that what the house is worth (be priced in forever). The longer the seller waits, the bigger loss he will take when he eventually sells the house.