IMO, what I think the most greedy application is the type of application that will eat all of your bandwidth whenever there is available bandwidth. There are two types of these applications : file transfer and virus (application ? May be)
If you do not limit the throughut of the file transfer and let the both ends as prefect machine that the file transfe will use all of your bandwidth. However, it is only an unicast application.
For the multimedia application, they will eat most bandwidth and multicast type, but it can be well-control by implement multi-cast and not impact non-using user.
Therefore, for any applications, if you can limit / control the usage, bandwidth then it will not be an issue.
For the GE to desktop, it really depends on your application traffic pattern and the infrstructure for server, desktop, any host. Moreover, most of the desktop, notebook come w/ GE port and the switch also built-in GE port. It is not expensive compare to earlier state. The most important issue is how to design the network to benefit the most of the application and the user. There is no prefect and fit to all design.
Just my 2 cents.
