Variables contain formulas: variable calculations
Calculate variable values based on math and text operations: use other variables, plain text, numbers, pricing table, and quote values to get to a new value.
Some examples would be
1. Generate document name variable based on template name, customer company name, deal value and expiration date.
2. Generate text based on a list of items a customer selects in a form, pricing table, quote or fields.
3. Calculate a downpayment size using document value and a custom multiplier.
4. Generate a new date based on a date in another fields or variable by adding a number of days/months to the original date.
etc.

Robert Fagnan commented
the ability to add formulas to tokens so they can auto fill # like for % based contracts

Yana Martynenko commented
Smart tokens
1) the token that illustrates the price of a specific product;
2) Can plus to each other and sum up to be the same as total amount in the pricing table. 
AdminMike Turke (Admin, PandaDoc) commented
Using a formula for date fields, specicially. Autofilling fields by date + N (days, months, etc.)

AdminKamari Ross (Admin, PandaDoc) commented
They would like dynamic variables that will autopopulate based on what product options the customer chooses in the document