yes taglal , otherwise i wouldn't have bothered my self reverse-engineering whatsapp and bought a cheap andro' to use whatsapp . i find it no use to have whatsapp as an APP on N900 , when we have something like telepathy which is easy to access and manage via a click and it's always running and wouldn't need much ram/cpu as a stand alone APP would .
your app might be closed by mistake , forget about you have to find your contacts from within the app instead of having them laying around on the desktop or the contacts list .
running a stand alone whatsapp app will require more used ram and cpu(means less battery time) and app that might malfunction on connection change 3g disconnects while travelling , non default IM tones/notfications/options ...
oops you restared and forgot to start the app , you want to go offline form all acounts ... wheres that app ...
dude i prefer purple plugin or telepathy or whatever it is ! at least you don't have to write that much code for a stand alone app (unless if you're aim is to collect donations or sell it ?) . at least telepathy already has xmpp protocol , so you just have to write the login/verification/registration part in a plugin for the N900 communication center -nice name haha-