This may be something about MicroTrend that's trying to be smart about detecting unsuspecting executables but I want to be sure. Here are the results I get from recent downloads of portable apps. Some of the apps I've tried downloading are: BonKEnc, PorkerTH, Pidgen, Cornice, Frets On Fire,
The detected malware/virus is called PAK_Generic.001
Aliases: Generic, Mal/Packer, W32/Sality.M, Win32/Puper.8ke!Trojan, Win32/Sality!generic
Is this MicroTrend trying to be over aggresive to keep me safe?
I don't use Trend Micro but can firmly state PortableApps.com have never released any software that contained viruses. There is a chance that in the forums someone of questionable character links to an infected app but as the apps you've designated are all officially released apps they have gone through a thorough testing process and has been signed by John himself.
For a more thorough way of checking your apps for your own peace of mind check the apps thru an online scanner. Here are some examples -
Hope this helps