Yes I agree it is quite similar, I discovered this application while doing market research. However, there are a couple of features that I have planned which will differentiate - such as a tighter email/Gmail integration.

Also, there is definitely space for both ClinchPad and Pipedrive to coexist.

Yep, just pointed out because I stumbled on Pipedrive. And actually Pipedrive was released before Trello.

That is interesting. Pipedrive has definitely done a good job so far!