Kobo have said that the Aura HD sold a lot better than they expected and that they planned to continue with it. I think the only reason it would disappear is if the couldn't source the screens. But, I could see a new version with a different shaped case.
The only hint of anything new coming is in the firmware package. "bin/kobo_config.sh" has the following code:
Code:
#!/bin/sh
PCB=`ntx_hwconfig -s -p /dev/mmcblk0 PCB`
case $PCB in
E60610D*) echo trilogy;;
E60QB*) echo kraken;;
E606B*) echo kraken;;
E5061*) echo pixie;;
E606C*) echo dragon;;
E606F*) echo phoenix;;
*) echo trilogy;;
esac
"kraken" is the code name for the Glo. Previous versions of the file only had the "E606B" line for the Glo. The other suggests there is a hardware revision coming for the Glo. It probably means internal changes like the Touch has gone through.