s_reynisson floated the theory that the next release will come with the next release of Windows. Helios has been mum.
Ultimately, TextPad does meet your needs or it does not. If it doesn't, you have the choice to find one that meets your needs. The only need I see that you have requested is the improved regular expression engine. There are plenty of editors that will provide that functionality.
Helios runs their business as they see fit, they own it, it's their decision. They are cognizant of the fact that their users want to know what is upcoming, when it's coming, how much it'll cost, if it'll make cotton candy and if it'll keep me from making logic errors. They have said they do not publish information about upcoming releases and have no plans to change that.
They are not developers
in absentia, they are developers working on the next release of their product. They have confirmed TextPad has not been abandoned. They have confirmed it is being actively worked on and will be released when it is ready.
You are entitled to feel that a single statement does not mean they have confirmed it is under development but I do not comprehend why you'd feel this way. Has Helios lied about their products before? "Foo will be released 28 Thermidore. Bar (tm) will have flying fizzywidgets!!!" To my knowledge, no, they have not. They do not make bold promises on delivery dates or features only to let their users down. They plod on doing their work and present us with the fruits of their labours when it is done.
TP5 might be deployed tomorrow. It might come next year. Those that don't know, guess it'll be end of the year, early next year. If you can wait, you'll wait, if you can't, you'll find another editor. Spewing vitriol because of the great injustice of waiting for a product to be delivered that has no set delivery date seems a waste of energy.
Finally, I'll quote myself because I still feel the same way. This was in a thread about when will TP5 come out.
I sincerely hope the answer is "when it's ready." I understand people's pain and frustration with no apparent redress of issues but think about what they're developing, a text editor. For those of you who make your living writing with it, would you rather have your gracefully aging, rock stable editor or one with the latest features that would make you happy except it keeps crashing and or corrupting your livelihood? For me, I'm far happier with a good and stable product versus one that is rushed out the door just to satiate the clamoring masses.