Yes and no. If the 6870 is a slightly faster 5850 with no improvements in power efficiency and higher price then it's a really stupid move. But I don't think the guys over at AMD are that dumb. But I agree, what AMD "needs" is a GTX460-killer which they already have really - just price the 5850 a bit more aggressive and there you have it.
Also I think the X7XX-cards have a very good reputation as being cheap, effective and with good performance. This is what Barts seems to be aiming at too so it would make sense to name it that way.
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