Based on the documentation it allows to:
• authenticate E*TRADE customers to the E*TRADE authentication servers.• manage trades and orders, including placing a new order, modifying an existing order,cancelling an order, or retrieving the status of an order.
I believe this is a key move for E*Trade; its API will allow it to drive more volume through its trading platform with probably less investment on advertising as for its own trading website and applications (but you will probably still enjoy the E*Trade babies on TV 🙂 )
The first 2 partners of E*Trade are CoolTrade and AbleTrend. CoolTrade allows user to create automated trading based on conditions they can easily create without using a programming language. AbleTrend is also an automated trading engine with built-in strategies, charting options and custom analysis.
There will be soon more partners for E*Trade: the financial analysis space is growing rapidly with companies like Trefis and Wikinvest. There is a real benefit for them in having their users being able to trade without leaving the platform.
And why not, new companies offering HFTaaS (HighFrequencyTrading as a Service) ; with the decreasing cost of computing, it does not seem to be such a far fetched idea…. (well you still need to be able to trade large volumes)