Nvidia won't launch the Geforce 8300 generation on the 17th of April. It will launch the Geforce 8500 card based on the G86 chip but not the whole range of entry level chips.
It will wait for ATI to unveil its RV610, a 65 nanometre chip and it will try to match its performance. We know that there is a big OEM demand for both products as the price is good. You have to pay less than $100 for both of them and the cheapest one should not be more expensive than $70, all DirectX 10 compatible.
Nvidia is a bit concerned about ATI's mainstream and entry level as ATI has gone 65 nanometre faster than anyone expected. Nvidia is still at 80 nanometre with its whole range of cards and its top end G80 is still 90 nanometres. Nvidia had enough time to shrink G80 from 90 to 80 but we still didn’t confirm such a move.