Hm, I wanted to report a bug but didn't find a bug report forum. So here's the feature request!
And here's the bug report (move the topic later...):
I always thought the speed information when copying files was just too high. Now I know it definetely is: You just can't copy 57 MB/s over a 400Mbps Firewire cable!
How about switching from a "current speed" to an "average speed", calculated by (amount of copied data/elapsed time) ?
And: I hereby renew my request for a copy queue!!
That's what the Help and Support forum is for. It's probably not worth having a dedicated bug report forum. Probably. 
There's already an average speed display, two lines below the current speed display.
The current speed can briefly and legitimately be greater than is possible than the transfer method allows, due to caching etc., but it should only be briefly like that and then level out (assuming there isn't a huge amount of caching and late-writes going on!). That said, I have a feeling you may be right that the progress dialog over-estimates copy speeds sometimes, although I've never cared enough to investigate.
The dialog's "time remaining" display is usually pretty accurate for me and I would guess that's calculated from the average speed, not the current speed, so looking at the average is probably best.
I second that, it would be nice. 
Probably non-trivial to add, and some of what a queue is useful for can now be done almost as well using file collections, but a proper queue would still be nice, one day.
All bug reports should be submitted to GP Software via the website (www.gpsoft.com.au). If you post them here they may be overlooked.
I'll investigate the numbers (compare with hand-timed values for large files) furthermore before deciding whether it's a bug or not 
That'll be some time from now, because I'm going on vacation...
And please: Implement that automatic stacking/queueing of copy processes. For now, the silly workaround is starting the parallel copy process, then immediately pausing it and manually reactivating it when the corresponding process is done.
So, back from the holidays. And now I've tested the copy information with a set of 7 video files accounting for 2.39GB of data. These were copied from a local ATA drive to an external Firewire-Harddrive. FireWire has a physical limit of 400MBps, resp. 50MB/s.
The copy took 116s and Opus told an average speed of 51,3MB/s. This is above the physical limit! And my Windows does not provide 2 Gigs of buffer memory. Additionally, 2568934588 Bytes divided by 116s calculates to roughly 21MB/s, an expected value for a close to full external drive with medium fragmentation.
Conclusion: the speed information from Opus is - simply said - totally wrong!
And: I cross-submitted this as a "program anomaly" on gpsoft.com.au