I'm sure that Smartbear folks will come along in time to indicate that they've taken the suggestion as, right now, you can't do so.
However, I think even making it a "standard" feature of TestComplete will be tricky. Considering the variable nature of software applications, how do you know how much time is left in executing a set of tests? A variety of factors can play into that timing. If the automation testing was precompiled where you knew ahead of time what tests were up and coming, it wouldn't be a problem. But this is "scripting" which executes in run-time without any sense of pre-compiled code.
The same would be true for the number of tests yet to execute. If TestComplete was designed in such a way where you had atomic tests where you know exactly, at any point of time, what tests are left to be executed, that wouldn't be a problem. But a Test Item in TestComplete's project structure could be a single test or could point to another test that executes a set of tests, or could be something like a call to a Data Driven loop that executes multiple tests based upon a CSV file in which the "number of tests" to execute isn't even defined within TC's code.
This is not to say it's not possible, just that I can foresee a lot of variables in doing something like this. Probably, in the short term, you can design your own indication in the "Indicator" object to display text that indicates what "remains" yet to be executed.
Just some thoughts...