When upgraded the though put from the storage solution will rise, my hypothetical question is how much data can I get into the switch by aggregating lines from the server.
I answered that long ago. N GigE has a theoretical cap of about 3.2Gb/s. That's it. That's the limit given those constraints. GigE cannot be aggregated faster than that and you introduce latency for going above a single link, so it's not all gain.
Bigger question, is your GigE actually your bottleneck? That would be very rare under normal circumstance but in Apple gear it is very, very unlikely.