Copper, aluminum prices could weaken in short term on back of slowing non-China demand growth, prospect of weaker China demand in 2Q07, say Macquarie commodities analysts; recent strong demand growth for these metals likely too great to be sustained, with reports from China suggesting overstocking in copper, aluminum: "We don't expect this (demand growth) pace to be sustained, and indeed there are reports of a substantial fall in copper buying interest in April and May." LME 3-month copper last at $7,735/metric ton, vs recent high last week around $8,100; aluminum at $2,850 vs peak hit mid-April of $2,930.