The young lovers took a break from each other in January, but were recently seen hanging out for the royal's 25th birthday.
Friends have also spoken of secret trysts and a flirty exchange of Facebook messages between the pair.
According to the Daily Express, plans are well advanced for the bash. Though one key detail still needs to be worked out – which of their favourite clubs is to host it.
“They’re looking at Raffles, Movida and possibly the Sanctum Hotel in Soho as potential venues,” says the source.
“There’s talk of charging their friends an entry price and donating the money to charity. It’s just a case of which venue and when.”
Harry and the pretty Zimbabwean regularly made headlines with their tender displays of affection in the past. So their split after a romantic break in Mauritius came as a surprise to many.
But both have had time to reflect during their separation and it could be that 2010 holds a more promising future.