Greenhouse Grower has put an online database of new varieties on their webpage - and it is searchable.
Go to http://www.greenhousegrower.com/varieties
On the left side of that page there is a list of 14 of the most popular genera. Click through some of those. The links will take you to articles and features. The focus is on commercial growing but the information is the most up to date you'll find pulled together in a single page.
So far there are 5,000 annual, perennial, shrub and tree varieties in the database. If you are looking for a different genus than those most popular 14, or want to search based on flower color or another of 15 plant characteristic, such as size, click Advanced Search or use the advanced search keyword searchbox.
Some of the links I clicked on were stubs that listed more links to check out. That's where I found the information I was looking for.