RIM/BB will have another Tablet if they want to compete as a Mobile Platform. I'm sure there are devices waiting in the wings. BUT first they need to prove that they can compete one just smartphones, if they can't do that what good would a tablet do.
Of course not having a tablet IS GOING TO HURT THEM. Many business are switching from laptops to tablets for their employes, so not having a devices on a platform that has the needed applications is allowing other platforms to move into an occupy the space that RIM wants to control. They really need to keep the current PlayBook in production and get BB10 on it quickly.
I disagree with your opinion. If BlackBerry want to be taken seriously again then a complete mobile solution was the way to go. It's no good having it waiting in the wings, people can't buy it from there ! And to compete with the big two they need to offer similar products. iPhone has the iPad and Samsung who have just become market leaders also have both Smart Phones and Tablet... If BlackBerry want to compete then they got to be on an even playing field.
There is an ever increasing need for mobile computing, tablets are fast becoming an essential part of that growth. The tablet is fast taking over from the laptop, they are literally go anywhere devices, they don't take up half the desk space in that board meeting, they don't encroach into your neighbors seat on the train. Easy to carry around, easy to use, just more convenient, and the more they improve the more they'll get used.
And that in my opinion is a missed opportunity, with good foresight and a dual release of a BB10 Smart Phone and Tablet (or at least an upgrade for the current Tablet) BlackBerry could have shown the company was serious about regaining it's reputation and again be seen as a serious competitor, if not market leader.
Again in my opinion, the current launch was quite low key compared to Apples launch events... Not simultaneously releasing in the USA was also a big fail. No BB10 upgrade for current PB's released along side the main Smart Phone release, and an admission that there are no current plans for a new Tablet is another fail.
I don't think BlackBerry will gain any more customers than they currently have, existing customers will upgrade but getting people to switch from the other two big competitors without being able to offer equivalent products is just wishful thinking.