i really hope that the Druid and Cleric spells will be done like in IWD. the Druid class was kinda useless in BG because Clerics had access to thier spells like Entangle, and Flame Blade if i remember correctly. Druids can be powerful, but i wonder if there will be specific quest so one can become a Grand Druid.

IIRC, their main quest will be to become Great Druid, not Grand Druid, since this would mean you have to face THE druid in the world.
You'll "only" become the greatest Druid of Amn, I guess :)

Also the XP cap of 2.8m keeps you from reaching 15th lvl to become the Grand Druid. I think it would he to hard to work all the Grand Druid powers into the game change form at will, exist on plane of earth, etc. Great Druid is the 'class' quest for Druid and defeating a 14th lvl Druid will be a cool battle. I hope they have more and better shapeshifting form than BG. But the spells will be split even more than IWD!

If you'll take the shapeshifter Kit,
you'll be able to shapeshift into a wherewolf once per day/4 levels and at 13th level you will be able to become a greater wherewolf!
The druids just can't get over 14th level because they would get extremely powerful abilities at 15th level and on.
Not because of the XP-cap or something...

Yes, you are right BG2 won't let the Druid reach 15th level due to the powers they'd get but the XP cap is the 'game' reason. the 2.8m XP cap will not let you reach 15th. You need 3 million XP. According to 2nd Ed. rule it take the Druid 1.5 million XP to go from 14th to 15th. And the powers are the reason why. If they make an expansion and raise the XP cap maybe we will start to see grand Druids, but until then I hope you have your paper and pencil handy. :)

And it would take more then half of the gaminghours of BG2 to gain 1.5 million exp. for just one character, and even if it could, the next cap is what? 4.5 million to become 16th level?

To reach 16th level a Druid needs only 500,000 XP. On reaching 15th level a Druid loses all their XP except 1 and starts earning it all over again. Another thing that would screw up a CRPG.

As you guys might know : there is only ONE Grand Druid across the realms. And wouldn't that be extreme coincidence that he just happens to reside in Amn ?
When a druid becomes a Grand Druid he gains immense powers, and when he becomes a Hierophant he even acquires even more impressive powers (travel through the planes at will, for instance).