Using AWS Autoscaling as dispatcher

I have been given the business logic of

1. A customer makes a request for services through a third party gateway GUI to an EC2 instance
2. Processing for some time (15hr)
3. Data retrieval

Currently this is implemented by statically giving each user an EC2 instance to use to handle their requests. (This instance actually creates some sub instances to parallel process the data).

What should happen is that for each request, an EC2 instance be fired off automatically.

In the long term, I was thinking that this should be done using SWF (given the use of sub processes), however, I wondered if as a quick and dirty solution, using Autoscaling with the correct settings is worthwhile pursuing.

Any thoughts?