I can't tell you exactly how long but it's usually pretty fast. They will either notify you directly or in this thread (or both) as soon as a verdict is reached.
Thank you Peter.
Today I received the verdict:
McAfee Labs Sample Analysis
Service Request: Malware Researcher: Showvik Chakraborty
Detected as Artemis!AB41424D6500
Identified: No Virus/Trojan
McAfee Labs, McAfee Labs, Bangalore, India
Thank you for submitting your suspicious file.
McAfee Labs researchers have examined the file in question and no malware was found.
McAfee(R) Artemis technology provides real-time protection that secures enterprises and consumers from threats as they strike and much quicker than traditional signatures can be deployed. As Artemis is updated in real-time there is no requirement to wait for a full DAT update nor to use an EXTRA.DAT intermediate solution. Simply wait approximately 30 minutes and this false will no longer exist or trigger on your system. Depending on the network settings you have or the caching involved between your system and ours it may take slightly longer for this false alarm to be resolved.
So, problem solved.
That's good. Wait a little while and then restore it from Quarantine and it should, hopefully, no longer be detected.
Thank you, Showvik.