DealAngel, a hotel search engine and aggregator that Tnooz profiled a year ago, will now be giving buy/wait advice to travelers based on market pricing trends for hotels.
The news was announced today. The feature works for more than 200 destinations in the US, Canada, Mexico, and Europe.
Says the company:

If prices are going up, DealAngel will warn you that prices have been rising and for how long, and will advise you to book now in order to avoid inevitably higher prices.
If, on the other hand, prices are showing a downward trend, you will see a flag suggesting you delay booking, and prompt you to enter your email address so you can be alerted as soon as the price begins to rise.
For example, lets say you want to plan in advance and are looking for a room in Vegas for New
Years Eve already in March.
But we have been observing a steady downward trend for the last month in Vegas market prices for this period of stay.
So, you are better off waiting until the prices bottom out. And we will alert you by email when this happens, so you can snap up that room at the best possible price. O
Word of this update comes only a couple of weeks after DealAngel rolled out a closed beta of its API of its hotel-deal-search technology to travel businesses so that they can find and promote their offers via their own sites. The trends information will be included into its API shortly.
It's only been six weeks since metasearch site Kayak introduced a price forecast tool for its US and UK users, similar to the airfare prediction service pioneered in 2005 by Farecast. It's curious that price prediction is suddenly a hot feature again.
DealAngel has received funding from Foresight Ventures.