They are publishing the prices now, just not in the main pricing page until the prices are current:

  The new prices for the colocation electricity/air conditioning rates are:
  electricity/air conditioning rate  old price\*  new price\*
  Germany  € 0.29/kWh  € 0.45/kWh
  Finland  € 0.12/kWh  € 0.22/kWh
  
  \*These prices do not include VAT.

But those are only the rates for collocation. The other server products (rented dedicated servers, VPS, etc) will become more expensive, too. Those prices are not yet announced, are they? (except the rough estimate of 10%)

Ah, it's true it isn't super clear... So "around 10%" and:

  The products that do not directly use electricity are not affected: IPs, domains, SSL certificates, racks, setup fees, and a few other examples.

At least they're not changing pricing for already provisioned products until 31st December.

yes, that's frustrating, but they would have to list both current and future prices or make some a list of changes instead of just updating the actual price when they go current