We are having our honeymoon July/August 2010 and have looked around quite a bit.
Mauritius: It's their winter there, however the temperature is still about 25 C, the sea is really warm. The sun sets at about 5.30pm. They get the least rain in this season. Mauritius is a tropical island with white sand, clear bluse sea, coral reef, gorgeous sunsets.
I have been given a quote by Holidays please and travel designers of £3550 for both of us all inclusive to Beachcomber Shandrani 4+* Hotel for 10 nights. Snorkling, water skiing, glass bottom boat rides, endelss champage, a la carte meals all included.
Holidaysplease quoted us £2800 for both of us for 10 nights at le cannonier 4* hotel all inclusive.
Cuba: It is really hot in July/August, hurricanes are infrequent at this time of year and are mopre likely to occur in september. This island looks extremely interesting and has white sands, clear blue sea, coral reefs. Havana city is supposed to be very cultural and well worth a visit.
We have been quoted £2350 all inclusive to Melia Cayo Santa Maria hotel 4+* for 14 nights. However, this hotel doesn't get great reviews on trip advisor.
My friend has just come back from Cuba on his honeymoon and said it was amazing!! They spent 3 nights in Havana and 11 nights at Hotel Paradisus de Oro 5* where he said they were treated like kings!!
Hope this helps, I know how hard it is to find your dream honeymoon as we are still looking. Going to get a quote for Paradisus tomorrow.

xxx