For my part, I think that Nada has a very valid point; there is a common thread running through most religions. It's not really surprising that the common ideas get recognized by adaptations of each others rites and holidays. On the other hand, it is rather ironic that a religion, such as orthodox Christianity, that proclaims itself entirely separate from all other religions - and that it is the only true religion, everyone else will be condemned to eternal hell for their heathenish ways - should be so quick to adopt those 'heathenish rites' in order to make 'conversion' to Christianity easier!
For those Christians, though, who just focus on the resurrection on 'Resurrection Sunday', perhaps with a sunrise service (which is supposed to be the time of day some of the women disciples discovered the 'empty tomb', and when Jesus is supposed to have made himself known to Mary Magdalene), the celebration is perfectly legitimate. For a 'liberal' Christian, who repudiates the notion of Christianity being the 'only way', and all other religions being 'evil heathenism', it is also legitimate to join the celebration of Jesus' resurrection with other 'new beginnings' traditions and symbols.