Although the Dalits have been included into Hinduism ( the caste system gives them no place ), there religious and spiritual isolation and exclusion continues as it has been going on for over three millenia.
Dalits largely do not have access to the temples that the caste Hindus patronize.
Further, other than in a couple of highly controversial cases, in which the Supreme court had intervened, Dalits never become priests of Hindu temples.
It is not as though law against this practise does not exist. It exists, but the community and social structure is so strong that Dalits simply do not dare enter caste Hindu-temples.
Their only access to temples is for those temples that have been specifically made for them alongwith caste specific Gods.
Ironically, even the Gods apportioned to them are inferiror in power, qualities and attributes as compared to the God's of caste Hindus.
This religious and spiritual isolation and exclusion, which basically does not accord them any religious dignity, is one of the reasons that Dalits convert to non-casteist faiths such as Islam, Christianity, Sikhism and Buddhism, among others.
Most Dalits in the Hindu fold, however, do not practise Hinduism. Rather they follow their ancestral religion which is largely animistic in nature.
There is also an increasing trend of conversion to Buddhism following a ongoing campaign among Dalits to convert out of Hinduism to escape caste.
NOTE: You can get very detailed information about the religous exclsion of the Dalits, along with information about their ancestral religions, the multiple reasons for including Dalits in the Hindu faith and about their conversion to other faiths, with examples and photographs, in the eBook 'The Truth About Dalits'.