Thank you for this question.
We do not have a spell checker component for WinForms
and I cannot give you an exact time frame when we will implement such component. Currently, we are focused on improving our existing controls and the TPF framework. However, we always strive to implement new features and components that our customers request. So, if more people request the same functionality we will raise its priority. I hope this helps. Should you have any other questions, feel free to ask.
the Telerik team