Mana producers are just as valuable as token producers in certain decks. Incubation Druid is a very powerful mana generator that can help Adapt itself on turn-four, and then keep pumping out three additional mana each turn.
Obviously, this kind of card should go into Bant and Temur lists that rely on ramping up and pushing out big creatures, such as Hydroid Krysis and Skarrgan Hellkite. But there is also a big chance of winning with the help of Simic Ascendancy.
In any case, Incubation Druid is a fantastic card for any ramp deck enthusiasts, so watch out for this little Elf at your next Magic event.