Nice
Maybe the depth as the background to the trades and is there any way of separating the buying and selling volume? A volatility indicator and MACD and kitchen sink and...
Most of the platform's api don't allow us to separate buying and selling volume, what we can do is putting some colors on the volume if the price increased or decreased during the volume timeframe (bitcoincharts style).
We plan to put some basic technical indicators very soon! Thank you for your feedback!
You definitely can tell on mintpal for example. My company is also working on such a chart analysis website and here is how we keep track.
Try running a jquery code to grab the recent 100 trades list from mintpal which indicates whether its a sell or buy action by denoting a 0 or 1. Repeat and save a copy every say 5 minutes and append the results to a server side json file. Convert to your database of choice, plot, enjoy. We append and save the data as we are working to offer a history, you may not have to?
Does this help?